bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Ground Vibrations Caused by the Shallow Subway
Authors: Mitroshin Vasiliy , Mondrus Vladimir , Sizov Dmitriy
Published: November 2019

The article presents an analysis of the results of vibration accelerations measurements on the surface of the ground above the shallow subway line. Amplitudes of vibration accelerations, obtained with the help of special equipment, can be used at the design stage of buildings and structures for the prediction of vibration levels in residential premises or production facilities. The data was carried out in the area between the stations “Belomorskaya” and “Khovrino” of Zamoskvoretskaya line of the Moscow metro. The process of attenuation of oscillations with increasing distance to the radiation source is considered, a graph of changes in the levels of vibration accelerations for several points within the sanitary protection zone of the subway is given. Numerical simulation of a fragment of a tunnel in the ground is done to define its natural modes of vibration. Conclusions are drawn about the origin of bursts in the vibration spectra in some octave bands at the time of passing the train.
Probable Approach to the Estimation of the Durability of Reinforced Concrete Structures
Authors: Berlinov Mikhail , Berlinova Marina
Published: November 2019

A method for calculating the durability of reinforced concrete structures under conditions of rheological deformation, taking into account corrosion damage, is presented, reflecting their real work under the combined effect of the load and aggressive environment, and also t the random nature of the effects. The possibility of considering the processes of long-term deformation of reinforced concrete from the standpoint of a probabilistic approach to the designation of the calculated reliability coefficients for the load and the material is shown. The regularity of the change in the maximum bending moment at different lifetimes is given, taking into account the rheological properties of materials by the example of the coating shell.
Influence of Boundary Conditions on the Stress-Strain State of a Corrugated Sheet Under Its Weight
Authors: Beskopylny Alexey , Kadomtseva Elena , Strelnikov Grigory , Shabanov Yaroslav
Published: November 2019

In this paper, the calculation of the corrugated sheet is reduced to the calculation of the strength and stiffness of the corrugated plate under its weight. The plate is made structurally orthotropic with different cylindrical stiffnesses in two mutually orthogonal directions. The curved middle surface is described by a fourth-order differential equation and is solved by the Bubnov-Galerkin method. As approximating functions in the expansion of the deflection, beam functions are also used to compare the Legendre function. It is shown that the beam functions give much worse convergence than the Legendre functions. The influence of the location of the rigid and hinged support, located in the direction of the guided line of the wave and perpendicular to it, was investigated. Rigid attachment along the side coinciding with the guiding wave reduces the deflections and the bending moments. The stress-strain state of a wavy and flat plate is compared with the same mechanical and geometric characteristics. The influence of the amplitude of the wave amplitude on the stress-strain state of a wavy plate is analyzed. It is shown that an increase in the wave amplitude leads to an increase in the strength and stiffness of a wavy plate.
Calculation of Dangerous Jumping Flows’ Energy Beyond the Dams of Hydropower Station
Authors: Solovyev Alexander , Solovyev Dmitry , Shilova and Liubov
Published: November 2019

The problem of reducing the energy of hydraulic jumps arising beyond the hydroopwer station dams is considered. A relationship is obtained for calculating the specific mechanical energy of the jump, taking into account the exchange of water masses between the roller and the transit flow. A comparison with the experimental data and the proposal of practical use is made.
Soil – Structure Interaction of Cylindrical Tank of Variable Wall Thickness under the Thermal Gradient Conditions
Authors: Lewinski Pawel M. , Rak Michal
Published: November 2019

The paper presents an effective method for the analysis of soil-structure interaction including the behaviour of cylindrical storage tank with varying wall thickness under the thermal gradient conditions. Elastic half-space and the Winkler model have been used for the description of subsoil. The soil-structure interaction is described by using the power series. A computational example of reinforced concrete tank loaded with temperature difference across the wall thickness is given. The analysis of a hydrostatically loaded cylindrical tank, performed for the model, incorporating elastic half-space shows decrease of radial displacements, as well as substantial changes in the distribution of bending moments compared to the Winkler foundation. A local increase of subsoil reaction around the slab circumference is observed for the case of elastic half-space, contrary to the Winkler model. In the case of a tank loaded with the thermal gradient, however, the solutions for both subsoil models do not differ significantly.
Numerical Studies of Elastomeric Isolator Performance Under Seismic Influence
Authors: Bunov Artem , Dorozhinskiy Vladimir
Published: November 2019

The article presents the studies of the elastomeric isolator performance under seismic influence. The solutions of the problems are obtained in the LS-Dyna software package. The calculations were performed by direct integration of the equations of motion using an implicit scheme. In the study of the elastomeric isolator, a three-dimensional finite element model was used. The diagrams of residual horizontal displacements of the support after the seismic influence are obtained. The inability of elastomeric isolators to self-return to the initial equilibrium position without additional devices is proved. The diagrams of acceleration of the support after the end of seismic influence are obtained. It is shown that the elastomeric isolators are an effective means of seismic isolation of buildings and structures. The dependence of the efficiency of the supports on the dominant frequency of external seismic influence is noted.
Theoretical and Experimental Researches of Spring Damping Flexural Oscillations for Beam Structures
Authors: Fomenko Serafim , Garanzha Igor , Tanasoglo Anton , Vershinin Vladimir
Published: November 2019

One of the main problems in the design of rigid bus in open switchgears is the problem of structural stabilization under the action of various dynamic loads. The implementation of rigid bus with large spans of tube showed a real risk of wind resonance for cylindrical tube structures (aeroelastic self-oscillations). This phenomenon is dangerous due to the fact that at low speeds of the wind flow, intensive oscillations of the tubes occur in the vertical plane, adding to the static loads an essential dynamic component. Its level is comparable with loads from its own weight of structures and can, in combination with other loads, will be the cause of stresses close to the limiting ones by the 1st group of limiting states. The problem of reducing the level of structural oscillations in many cases is associated with the need to increase rigidity and reduce the material consumption of structures, however, it is important to fulfil the technological requirements of the operating conditions and protect people from the harmful effects of oscillations. The article highlights some of the main ways to damp oscillations of rigid bus structures. Is given a mathematical model of the simplest single-mass spring inertial dynamic oscillation damper. Experimental studies have been carried out on the joint work of the rigid bus structure with the spring damper. Has been confirmed the effectiveness of spring dampers using, both outside and inside the tube-bus.
Difficulties in Operation of Elevations in Large-Panel Buildings
Authors: Knyziak Piotr , Kanoniczak Marcin
Published: November 2019

The article presents problems in facade walls operation of large-panel buildings. Examples of irregularities resulting from the initial poor quality of precast elements and assembly errors are presented, as well as problems arising as a result of repeated renovation and modernization works. The problems before and after wall insulation were discussed in greater detail, resulting from leaking joints of precast elements. Biological threats resulting from the influence of algae, lichens and vines on the façade material are presented. The general technical condition of the facade of a selected group of buildings was compared in studies carried out at an interval of 11 years.
Formal Expert Examination of Welded Joints Quality at Oil and Gas Industry Construction Projects
Authors: Didkovskaya Olga V. , Mamaeva Olga A. , Ilyina Marina V.
Published: November 2019

Now construction engineering and engineering research set much store by determination of completed works and building structures quality. At the same time, there are no special approved methods of quality determination. In this paper the authors are going to draw up a methodology of assessing the quality of welded joints of pipeline structures in case these works have to be examined forensically. The researchers analyse legislation requirements on forensic examinations technical regulations and practical experience and offer a methodology which makes it possible to conduct a formal expert examination in a proper legitimate way.
Assessment of the Technical Condition of a Deteriorated Heat Pipeline Overpass before Repair
Authors: Lutomirska Marta , Lutomirski Tomasz
Published: November 2019

Pipeline overpasses are special structures common in many fields of industry. The magnitude and origin of damages to a heat pipeline overpass are presented and discussed. One of the more typical elements, a vertical truss with the smallest cross section, was chosen for an assessment of its resistance. The former design codes, valid at the time of the design, construction, and use of the overpass significantly differ from the current design codes. The calculations were performed with the use of three design codes, which were valid during the period of 60 years of use of the overpass. The results are summarized and compared.
State-of-the-Art on Fire Resistance Aspects of FRP Reinforcing Bars
Authors: Protchenko Kostiantyn , Szmigiera Elzbieta , Urbanski Marek , Garbacz Andrzej , Narloch Piotr , Lesniak Przemysław
Published: November 2019

The behaviour of Fibre-Reinforced Polymer (FRP) bars and Fibre-Reinforced Polymer reinforced concrete (FRP-RC) members under fire exposure is quite different from conventional means. This may be attributed to the complex behaviour of the bars when they are subjected to fire, as well as to the complexity of fire test procedures. The thermomechanical properties of FRP bars depend on the chemical composition of their constituents, their interface performance and the production process. The choice of the type of fibres and matrix with characteristics suitable for the desired purpose, as well as their balanced proportions in FRP bar can be the key factors affecting the overall resistance of an FRP element in the event of fire. The work presents a theoretical background and is intended to identify existing gaps in knowledge to justify the need for the present study.
Impact of the Fire and Acoustic Protection on the Composition of Lightweight Wood-based Cladding Envelopes in the Construction of Apartment Buildings in Passive Standard
Authors: Iringova Agnes , Vandlickova Dominika , Divis Michal
Published: November 2019

The aim of the paper is to analyze structural systems of wood-based buildings and their applicability in the construction of apartment buildings in terms of fire safety. It also describes the optimization of the material base of thermal insulation and cladding materials in terms of fire and acoustic insulation and optimization of insulation and cladding materials in terms of sustainable development. The result is assessment of their suitable application in the construction of apartment building depending of the fire height and Comparison of their physical parameters in terms of thermal and acoustic insulation.
Approximation Method for Evaluation of Strains and Forces in LTP Reinforcement of Embankments on Columns
Authors: Gajewska Beata , Gajewski Marcin
Published: November 2019

This article presents a method of approximate finding of forces and strains resulting from the so-called membrane effect in the reinforcement of the transmission layer of embankments located on a soft soil improved by columns (rigid inclusions). The model task needed to determine the characteristic values in geosynthetic reinforcement supported on rigid columns was formulated. The reinforcement is treated as an isotropic membrane, in which the strains are determined using the formula for the length of the curve, i.e. it deviates from the assumptions of the small strain theory. Spatial problems are reduced to equivalent one-dimensional static tasks for analysis using the isotropic membrane theory. The closed form solution of this task exists only in the case of uniform load. For other types of loads, it is necessary to approximate the formula for the length of the curve occurring in the expression defining the strains in the membrane, e.g. using the Taylor series, and then solving the strongly non-linear equation in which the membrane tension force is unknown. The article presents the analysis of the effect of the length curve approximation with usage of the Taylor series on the accuracy of the results obtained. The presented analysis is very important from the point of view of standard engineering calculations needed to design the reinforcement of the transmission layer in the case of embankments located on soft soil reinforced with rigid inclusions.
Methods of Surveying the Inlet and Outlet Channels of the Spillway Dam at the Hydroelectric Power Plant
Authors: Evdokimov Sergey , Seliverstov Vladimir , Orlova Alla , Rakova Elena
Published: November 2019

The paper deals with methods of the hydroacoustic survey of the outlet, inlet channels of the spillway dam at the Zhigulevskaya hydroelectric power plant and waters adjacent to the earth-fill dam. The survey of underwater parts of hydraulic structures and the bottom of the Zhigulevskaya hydroelectric power plant was carried out with the help of the hydroacoustic method and included full coverage of all surfaces of underwater parts. All deformations of the surveyed surfaces and all foreign objects on them, the size of which exceeded 0.5 m in height, were recorded. The survey of the waters was carried out with tacks of basic coverage based on a system of parallel tacks oriented in parallel and perpendicular to the axis of the structures. The devices used for the survey allowed obtaining coordinate increments in the plan and along the height at the distances of the surveyed waters with an accuracy of not more than 0.1 m and a confidence coefficient of 95 %. When performing the set of works, it became possible to conduct the hydroacoustic survey and create a bathyorographical map for the inlet and outlet channels at the spillway dam. The hydroacoustic survey allowed making a sample-based assessment of the condition of concrete slopes of the outlet, inlet channels at the spillway dam, of the HPP as well as the condition of slope protection at the earth-fill dam in the waters of the upper pool. The analysis of the survey results helped to evaluate the dynamics of the deformation process taking place at the bottom of the outlet, inlet channels at the spillway dam, the HPP and in the waters around the earth-fill dam. As a result, measures for the operational reliability of structural elements in the outlet, inlet channels at the spillway dam, the HPP and in the waters around the earth-fill dam were developed. In addition, according to the results of the hydroacoustic survey of the outlet, inlet channels at the spillway dam of the Zhigulevskaya HPP, a new bathymetrical map was created.
Comparison of Chosen Geodetic Method for Measuring of Swimming Pool Length
Authors: Chromcak Jakub , Cesnek Tomas , Izvoltova Jana
Published: November 2019

Lengths are one of the basic geometrical quantities measured in geodetic works. The most important precondition for proper measurement is an accurate knowledge of length measures, calibrated standards, comparative devices and length measuring instruments. Nowadays, there is some kind of technological boom in all technological spheres. The measured length can be partial result of another kind of measurement like the 3D scanning. The aim of article is to compare measuring methods for measuring of swimming pool length.
Effect of Stone Columns on the Behaviour of Single Pile in Soft Clay Soil
Authors: Znamenskii Vladimir , Abd El-Naiem Mostafa Abdou , Towfeek Ahmed Rushdy , Hegazy Osama
Published: November 2019

Soft clay is consolidated upon any slight change in the effective stress. Consolidation and settlement of soft clay surrounding a pile usually drag the pile down ward. The down drag movement adds additional loads to the already loaded pile. This force is expressed as a negative skin friction. Negative skin friction starts from the pile head to a neutral depth depending on the interface properties. This depth is referred to as the neutral plan. This paper presents a study on the effect of stone columns on the behaviour of piles during consolidation of soft clay soil. For this goal the experimental tests were done to study effect of stone columns on the behaviour of single pile embedded in soft clay. The study concluded that the neutral plane is located closer to the end of the pile as the end bearing increases. Stone columns are considered one of methods used to reduce the settlement of soft clay soil, and helps to speed up the rate of consolidation by shorting the length of drainage path within the soft clay layers, and then decrease the relative displacement between the pile and the surrounding soft soils. The use of stone columns reduced the amount of negative friction developed along the pile depth.
Problems and Prospects of Billing Systems in the Housing and Utilities Sector of Russia
Authors: Degaev Evgeniy
Published: November 2019

The article deals with the problems and prospects of using billing systems on SaaS (software as a service) software complex in the housing and utilities sector and civil engineering. As consumers are considered both individuals and construction companies. The construction also uses utilities. These utilities also need to be paid. Currently, “thin billing” is predominantly used in Russia, where each service provider applies its own metering system. The supplier independently performs calculations, and then transfers the information to the Financial Settlement Center in the established format, where after a billing document is drawn up and sent to the consumer of utilities. This format has an advantage only for suppliers, as they can change the tariff corridor and set flexible conditions. From the point of view of the consumer, such a format does not allow tracing all settlement schemes. And in the event of failures or technical errors, the consumer will have to find out the reasons in all instances as before. In order to eliminate bureaucratic processes, it is proposed to implement turnkey billing systems in a “one window” format, where all operations of the housing and utilities industry are consolidated into one platform. Despite proven reliability, billing systems in Russia require large financial investments to ensure complete information security.
Modified Cement Systems for Finishing Coatings
Authors: Tkach Evgeniya , Nurbaturov Kanapiya , Kulibayev Askar
Published: November 2019

The processes of development of finishing coatings on the basis of cement colloidal systems are determined. The influence of processes of modification of colloidal cement systems on the properties of decorative coatings is studied. It is shown that the introduction of modifying additives in combination with mechanical activation allows using the optimal technological parameters of processing to give colloidal cement composites the necessary properties and increase the resistance of protective decorative coatings. The joint activation of the components of colloidal cement adhesive with a modifying additive leads to an increase in the strength of the samples at all times of hardening. Studies have shown that modifying additives and fillers have a positive effect on the thixotropic properties of the system and contributes to the formation of the hydrate with colloidale particles, which leads to hardening of the reinforcement system of a composite. Found that the addition of metakaolin enhanced the activity of fine cement systems. Studies have shown that fillers have a positive effect on the thixotropic properties of the system and contributes to the formation of the hydrate with colloidale particles, through which are formed the spatial packing, which leads to hardening of the reinforcement system of a composite.
Study of the Glaze Layer Surface of Ceramic Tiles Before and After Ion-plasma Deposition of Protective-decorative Coating
Authors: Chumachenko Natalia , Tyurnikov Vladimir , Khafizov Il’nur
Published: November 2019

The protective coating deposited by ion-plasma sputtering have a very vivid aesthetic and decorative properties that make them attractive for solving design problems, and also enhance the operating characteristics of the products (increases strength, hardness, durability). The main stages of obtaining protective and decorative coatings by electric arc method, namely condensation by ion bombardment (CIB), are considered. The properties of the cathode substance, and hence the compounds formed by these substances, depend on their position in the periodic table. The dependence of the coating properties and features of the electronic structure of the material from which the cathode is made is analyzed. The effect of ion-plasma treatment of the surface of glazed ceramic tiles on their properties is studied. The distinctive features of the structure of the glaze layer of domestic and foreign ceramic tiles are revealed.
Basic Theorizes of Regulatory Impact Logistics in Investment and Construction Sphere
Authors: Sborshikov Sergey , Bobin Alexey
Published: November 2019

Modern systems and subsystems of management are characterized by complexity of structure and increasing interlacing between its elements that demands knowledge of specific dynamic properties, both all system, and each subsystem, their behavior in space of a national economy. The paper presents the definition of boundaries for the preservation of dynamic stability, as well as the methodological basis for the development of methods for maintaining the trajectories of sustainable development of logistics management systems in the field of investment and construction activities.
Targeted Management of Performance Indicators of the Park of Control and Measuring Equipment Used in the Construction and Housing and Public Utilities Sectors
Authors: Khayrullin Rustam
Published: November 2019

The mathematical model is presented for the purpose of management the performance indicators of the park of control and measuring equipment used in construction and the housing and public utilities sectors. The model is based on performance management algorithms that ensure a smooth monotonous transition of indicators from current values to the required values for a fixed period of time. The smoothness of the transition is ensured by using the pieces of monotonic degree functions as a reference plan. The developed algorithms make it possible to effectively build preliminary target plans, as well as to make refined plans in the event of underfunding (refinancing) at individual planning stages. The main directions of development of the technical base of park of control and measuring equipment are the modernization of existing samples and types of control and measuring equipment as a result of scientific research and development work, as well as the purchase of new advanced control and measuring equipment to replace obsolete samples of control and measuring equipment. The article presents the results of mathematical modeling of the specified directions of development of the technical base of park of control and measuring equipment.
Formation of the Organizational Structure Based on Project Matrix
Authors: Morozenko Andrey , Krasovskiy Dmitriy
Published: November 2019

This article sums up the results of researches, which are aimed at exploring the ways to form an effective organizational structure of a large-scale construction project based on key events matrix. New methodology of organization design is based on informational paradigm that allows to consider production process as the complex of technological operations based on production ties and logical connection that are synchronized in time and realized by different participants of construction project. This allows to introduce a concept of project’s key events matrix which is a functional model of the organizational structure of project’s executive system. The project matrix is considered as a program graphical representation, which is implemented by management system in order to ensure that organizational structure corresponds to a specific phase of construction project’s implementation.

The article reflects the properties of key events matrix, which helps to improve the quality of organizational design and reduce the time of its creation. Depending on the level of construction project’s decomposition or its detalization, the key events matrix can also have several levels of detalization, so key events are always reflected in the matrix, no matter what level it takes. Thus, we find the scaling effect in the properties of the matrix. In addition, the project’s key events matrix has the property of “stitching”, which means is a possible to supplement it with new events at any stage of the construction project. The use of new methodology in order to form the organizational structure of construction project makes it possible to reduce the production time of design works as well as improve their quality.1. Introduction
Natural and Synthetic Polymers Used in the Preservation of Historical Stone Buildings
Authors: Terlikowski Wojciech , Sobczyńska Ewa , Gregoriou-Szczepaniak Martyna , Wasilewski Kacper
Published: November 2019

In this review, the rules applicable to the preservation of stone monuments, referring both to the selection of appropriate materials (compatibility principle) as well as the repair process itself was discussed. A wide range of natural and synthetic polymers used for reconstruction purposes has been described. An example of the use of polymers for hydrophobization treatment of historic stone structures at one of the archaeological sites in Tyritake, Russia, carried out by Civil Engineering Faculty of the Warsaw University of Technology is also presented.
Experimental Research of Corrosion Effects on Steel Bridges
Authors: Jancula Miroslav , Vican Josef , Spiewak Anna
Published: November 2019

Bridges are significant elements of the transport infrastructure, so they should be in operation throughout the whole design life. Therefore, it is necessary to know the main causes of damages and failures of the bridges. The corrosion of structural steel caused by atmospheric influences as well as the bridge exploitation cause a cross-sectional reduction of structural elements and, consequently, a decrease of the resistance of steel bridge members. The article deals with corrosion and its impact on steel bridge elements in order to use this data for developing actual corrosion model appropriate for design of structures on durability.
Specifics of Bending Priority Road at Unsignalized Intersections
Authors: Kocianova Andrea , Pitlova Eva
Published: November 2019

Unsignalized intersections with a bending priority road are common in Slovakia’s road network. Various specifics are associated with these type of intersections compared to conventional intersections with a straight priority road. There are different priority ranks for traffic streams, more complicated traffic situation, different traffic flow characteristics and driver behaviour. The problem is that only a few studies to date have addressed to this type of intersections and their specifics. Therefore, some traffic flow characteristics such as the speed of major-stream vehicles; and driver behaviour such as compliance with traffic rules, influences of potentially conflicting traffic streams on minor-stream drivers, and the driver gap-acceptance characteristics (critical gaps) at unsignalized four-leg intersection with a bending priority road in Zilina were surveyed. The results show vehicles moving along the bending major street about 40% slower than the city speed limit of 50 kilometres per hour. About 16% to 25% of drivers turning right from the major street did not signal the change of direction. About 16% of priority rule violations were recorded at the least priority minor approach during peak hours and long delays. There are two times more potentially conflicting traffic streams compared to intersection with the straight priority road and the effect of these potentially conflicting streams has ranged between 20% and 60%. The paper demonstrate that the values of critical gaps for the same movements more significant differ according to major/minor street and rank of priority, and critical gap values for straight traffic streams of third and fourth priority rank were determined to be about 0.4 to 0.9 second higher in comparison to the values for conventional rural unsignalized intersections. This new findings cause reduction of minor stream potential capacity and traffic safety.
The Economically Active People in the Transport Process
Authors: Drliciak Marek , Celko Jan , Cingel Michal
Published: November 2019

Traffic-planning process, the traffic management process requires continuous collection and analysis of traffic data. The direct measurement usually determines the volume or speed of the traffic flows. In comprehensive traffic, assessment is necessary to know the causes of mobility and its characteristics, the group of habitants and purpose of the trips, above all. The article deals with the mobility characteristics of economically active people for work and their application to calculations using discrete functions. The data are based on an extensive transport-sociological survey of the mobility of the inhabitants of the Žilina region. The first part of the article is devoted to the basic survey data. The core of the article is the application of discrete choice models in the process of trips generation and modal split.
Mixture of clay and telethong as environmental friendly binder
Authors: Ruswandono  , Paing J , Andaryati
Published: November 2019

This research was inspired by the phenomenon of local wisdom that has existed in the archipelago. In Bali using cow manure as stucco for finishing their walls. In the village of Teraseng, Menganti - Gresik Regency uses the waste as a cover for the walls of their houses from woven bamboo. In the village of Sade - Mataram, Lombok Island, a mixture of cow dung waste (telethong) has been used as stucco on the floor of the house. This paper examines to the extent that scientific evidence can be made of existing local wisdom. The combination of silicate-rich clay and telethong has been tested on mortar specimen. Sample mortar was physically and mechanically tested at 3, 7, 14 and 28 days. The results of the trials showed that the binding material produced by a combination of clay and telethong was still below the PC cement sample strength which was used as a control variable. In combination of clay and telethong, compressive test results show that the greater the telethong level, the lower the compressive strength produced. The test sample with a percentage of 25% gives the maximum results with ratio of 6% of the PC cement sample value as the control variable.
Repair of reinforced concrete beam by adding external reinforcement
Authors: Dewi S M , Susanti L , Triyuliani N I , Saputra A
Published: November 2019

The negligence in construction are usually due to error in replace or calculation of required reinforcement. The mistake known after construction and must be corrected as soon as possible. Some actions should be taken namely, add some pretension, augmented the beam size, use the FRP, and add some external reinforcement. Studies on rehabilitation and retrofitting are gaining importance due to the need for restoration of partially damaged structures due to wind load and earthquake. To prevent any disaster during the future earthquakes, the existing deficient buildings need to be retrofitted. The external tension reinforcement added when the flexural beam capacity inadequate, and the stirrups added when the shear beam capacity inadequate. The adding with external reinforcement also done after some tensile failure or cracks in the beam. In this case some damage of concrete must being consider in reducing stiffness and strength. The objective of this research is studied about the adding of external tensile reinforcement and stirrups after tensile failure and explore the influence of those action to the beam and then compared the strength, stiffness, ductility and crack pattern of beams before and after retrofit. The specimens were 12 original beam, and 12 retrofitted beam. The original beams have dimensions of 15 cm x 15 cm x 100cm, the tensile reinforcement were 4ф6 and compression reinforcement 2ф6. The stirrups were ф6-200 along the beam. Retrofit strategies were adding bottom tensile reinforcement 2ф6 and 3ф6, and adding stirrups ф6-60 in the shear span. The experiment shown the increase of beam ultimate load after retrofitting, but decrease the ductility and stiffness of the beam. The pattern of cracks also changed between original and retrofitted beam.
The effect of copper-based catalytic converter with circular tube shape on exhaust emission of Yamaha Vixion 1PA
Authors: Shoffan I A N , Sumarli S , Nauri I M
Published: November 2019

Indonesia is one of the countries with the third highest air pollution in the world. The biggest contributor air pollution is produced by motorbikes by 60-70%. One the causes of increased exhaust emission is widespread use absorptive exhaust that designed without catalytic converter. The aims of this research is to determine the effect of copper-based catalytic converter with circular tube shape on exhaust emission of Yamaha Vixion 1PA. This study used an experimental research design. The objective of this research is copper catalyst with circular tube shape model. The research instrument used the gas analyzer HG-510 as a test tool for data collection of exhaust emission. Data analysis using inferential statistical techniques paired sample T test through the SPSS 24 statistical analysis application. The results showed that the addition of copper catalytic converter with a circular tube shape model can reduce CO exhaust emission by 16.67%, whereas for exhaust emission HC can be reduced by 32.54%.
The analysis of alpha parameter on Nakayasu Synthetic Unit Hydrograph in Timor Island watersheds
Authors: Krisnayanti D S , Bolla M E , Nasjono J K , Wangge M J M
Published: November 2019

Benenain and Noelmina river are rivers on Timor Island which have large watershed area. With a large watershed area, it is necessary to observe and calculate the peak flood discharge deeply. One of the methods used for calculate the peak flood discharge Nakayasu Synthetic Unit. In calculating the peak flood discharge with Nakayasu Synthetic Unit Hydrographic Parameters difficulties often encountered in determining the accuracy of the α (alpha) value coefficient. To calculate the α (alpha) value coefficient required data in the form of area and length of river. The results of analysis using software IBM SPSS version 23 the (alpha) value coefficient on Timor Island can be obtained using equation α = 2,461. (L)−0,417. (A)0,214 so that the α (alpha) value for each watershed varies depending on the size of the watershed and the length of the river. Thus, with the confidence level of the results of the analysis is 95% and the coefficient of determination (R2) is 0.826 then the watershed area and river length give an influence of 82.60% on the value of α (alpha) obtained.
The strength properties of high calcium fly ash geopolymer specimens incorporating mud-volcanic and limestone variations
Authors: Wardhono A , Risdianto Y , Sofianto M F , Nur M T , Pradipta A H
Published: November 2019

The use of mud-volcanic and fly ash as cement replacement materials is one alternative solution to overcome environmental issues due to the mudflow disaster and polution from cement production process. This paper objective is to identify the use of mud-volcanic and class C fly ash with high calcium content as waste materials in the development of fly ash geopolymer incorporating limestone. The variations of limestone to fly ash are 0.10:0.60, 0.2:0.5, 0.30:0.40, 0.40:0.30, and 0.50:0.20, respectively. The mud-volcanic ratio was kept at 0.30 to maintain the total weight of specimen at 1.00. The compressive strength was performed at 7, 14 and 28 days age, and the specimens were cured at ambient temperature. The depth penetration test was performed by vicat test. The results show that the highest strength value of 16.38 MPa was achieved by fly ash/mud-volcanic geopolymer with ratio of limestone to fly ash of 0.30:0.40. The initial setting time of 90 minutes indicates that the early reaction of fly ash/mud-volcanic geopolymer shows a comparable setting time to the normal concrete with initial setting time of 45 minutes. These results indicate that fly ash and mud-volcanic can be used as cement replacement materials.
The effect of reinforcement bridging on the elastic fracture energy of concrete
Authors: Patty A H
Published: November 2019

Failure of structures may be analyzed based on strength criterion or fracture mechanics criterion. Strength criterion deals with material resistance beyond the critical conditions such as yield, and ultimate strength. In fracture mechanics the critical condition is defined by toughness which can be stress intensity factor (K) or fracture energy (G). This study explores the critical point during loading up to the limit of elasticity based on linear elastic fracture mechanics – LEFM. However, nonlinearity frequently appears due to the existence of a relatively large fracture process zone – FPZ located at the crack-tip. The assumption of LEFM in quasi – brittle material such as concrete is therefore limited to large size structures only. The well-known approach to obtain the fracture energy Gf for infinite large structures is size effect law – SEL. Gf is defined as the specific energy, i. e. energy per unit crack plane area. This is elastic energy which is linear. To answer a question whether reinforcement affect the elastic fracture energy, a research was conducted following the principles of work-of-fracture – WOR using the RILEM Specification Test Method. Three-point-bend beam specimens were made of normal concrete, subjected to monotonic load P, until they failed. P–u relationship prevails the real work. The elastic fracture energy based on WOR that is

G

F
−
e
l

R

was found by divided the area under P–u curve of elastic range with ligament. The result is,

G

F
−
e
l

R

equal to 397.87 N/m for beam A1 (bending failure l/h=5.5), 133.6 N/m for beam B1 (Shear failure, l/h=5.0). 101.93 N/m for beam B2 (shear failure, l/h=5.0), 153.75 N/m for beam B3 (shear failure, l/h=5.0). The greater value

G

F
−
e
l

R

comparing to Gf implies that reinforcement affect significantly the elastic fracture energy.
Pervious low-calcium fly ash geopolymer concrete using gap-graded limestone coarse aggregates in ambient curing
Authors: Simatupang P H , Adu M A J , Sadukh Y M I , Jonbi
Published: November 2019

This paper describes the research of pervious geopolymer concrete using limestone from Timor Island in Indonesia as coarse aggregate. No sand was used to make this pervious geopolymer concrete. Two types of crushed limestone aggregates used were coral limestone (organic limestone) and limestone (calcilutite). Abrasion losses of the aggregates using Los Angeles Machine test were 18.9% for limestone (calcilutite) and 34.98% for coral limestone. Those aggregates had many characteristics such as 10-20 mm of diameter length, angular shapes and apparent specific density 2.74-2.75. The mass ratios of aggregate to geopolymer paste were varied from 2.86 to 6.91. To make the geopolymer paste, it was used Class F or Low-Calcium Fly Ash from Bolok-Kupang Coal Fired Power Plant as a rich silica-alumina of precursor material. Meanwhile, the mass ratio of natrium silicate solution to natrium hydroxide solution 10 M was 1.0 and the mass ratio of fly ash to alkaline solution was 2.0. Ambient curing was applied to all specimens. Mechanical characteristics obtained at the age of 28 days of hardened pervious geopolymer concrete were: (1) compression strength, (2) splitting tensile strength, and (3) abrasion losses using Los Angeles Machine Test. Besides, density of hardened specimens were also obtained. In addition, the comparisons of mechanical properties of pervious geopolymer concretes using coral limestone and limestone (calcilutite) as coarse aggregate were also conducted. According to the results of this research, it is feasible to make pervious geopolymer concrete using Timor limestone as coarse aggregate due to its mechanical characteristics.
Experimental study of precast concrete beam-to-column connection under sustained loading
Authors: Noorhidana V A
Published: November 2019

The long-term behaviour of an exterior precast concrete beam-column (PCBC) connection has been investigated in this study. The connection consists of a precast U-beam, precast column with corbel, and interlocking bars to connect the precast column and precast beam. The specimen was tested under sustained loading for 120days. The crack propagation, the development of strain and the deflection of the beam was observed throughout the test. The results show that the PCBC connection behaved in similar manner to correctly designed conventional reinforced concrete members under long-term loading. Flexural cracks occurred within the plastic hinge region of the beam. No cracks occurred in the joint core and column. The long-term behaviour of the PCBC connection was influenced by shrinkage and creep. The significant increase of deflection occurred in the first 15 days of testing, which is 37% of the total long-term deflection. The experimental long-term deflection has bigger value than the theoretical deflection evaluated using ACI 318-08.
Risk study on supply chain management in construction (Case study: Building projects in Indonesia)
Authors: Nurdiana A , Sholeh M N
Published: November 2019

The concept of supply chain in construction is very influential on the improvement of projects performance. In outlining the problems in the supply chain, it need to be identified the risks therein related to the smoothness of the supply chain process. Risk is an event / uncertainty condition, when it happens may lead to positive or negative impact [1]. The purpose of this study are to determine the identification of risks on supply chain in construction projects, analyze the risks, and analyze the response of risks. Primary data obtained through a questionnaire and interview methods. Data processing method that used in this research were Promethee method for risk analysis, and descriptive statistical methods at risk response. From this research, it is known that the identification of risks at supply chain in construction projects can be seen from the potential failure of achievement of Key Performance Indicators in Supply Chain Management (SCM). From risk analysis with Promethee method, it is known that the highest risk in SCM is the change of price from sub-contractors. Based on the analysis for risk response, it is known that the contractor has developed mitigation measures to risk response.
Experimental analysis on the performance of concrete beam due to the effect of knitted bamboo reinforcement ratio
Authors: Setyowulan D , Nuralinah D , Arifi E , Prasetyo F D
Published: November 2019

Bamboo is an abundant material in Indonesia which has been previously studied as a construction material and reinforcement. The performance of concrete beam with knitted bamboo reinforcement are studied, especially on the flexural strength and crack behaviour. Three concrete beams with the dimension of 15 x 25 x 160 cm and three slices of bamboo in each knit are investigated. The outer skin surface of this knit is soaked NaOH with sikadur and sand as coating material. The results found that the flexural strength of concrete beam for the first and second model was 3.56 MPa and 6.15 MPa, respectively. Pure bending crack occurred on all concrete beam models.
The dominant factor causing potential evapotranspiration in Malang raya using geographic information systems
Authors: Rahayuningsih T , Idfi G , Anindyasari A , Sukriyadi
Published: November 2019

The water resources management in Malang Raya is very important, because this area still has a lot of agricultural land. Agricultural land needs evapotranspiration maps. By now, there has been no research on the dominant determinant of the value of potential evapotranspiration in the Malang Raya area. Therefore research on the main factors that determine the value of potential evapotranspiration is needed. Purpose research: 1). Discovering the irrigation area that has the lowest and highest potential evapotranspiration value in Malang Raya; 2). Determine the dominant factors that affect the potential evapotranspiration value of irrigation areas in Malang Raya. The method to predict and calculate the amount of Potential Evapotranspiration (ETo) is Penman Method. The main determinants of potential evapotranspiration are mapped using Geographic Information Systems (GIS). Determination of the dominant factors that influence potential evapotranspiration was tested using SPSS. Conclusion: 1). The lowest potential evapotranspiration value were in Blimbing and Kedungkandang Districts from 3.46 to 3.61 mm / day. While, the biggest values were in Batu and Junrejo Districts with values of 6.32 to 6.33 mm / day; 2). The dominant factor affecting the potential evapotranspiration value is the air humidity (RH) factor of 46.4%.
The addition of lamella in anaerobic baffled reactor used for decentralized municipal wastewater treatment
Authors: Yulistyorini A , Yuaniar M C , Mujiyono M , Suryoputro N , Sukarni S
Published: November 2019

An anaerobic baffled reactor (ABR) represents a low-cost system for decentralized wastewater treatment in a developing country. Despite the advantages of ABR units such as low operating and maintenance costs, this system requires sufficient land to construct it. In particular of an urban area, land availability is limited and therefore acquire modification in ABR design. This study aimed to test the addition of lamella for further reduction of solids particle in domestic wastewater, and therefore it could reduce the size of ABR settler. A lab-scale of an ABR lamella with a dimension of 75 cm length, 20 cm width, and 40 cm height used in the experiment. A 20 L/d of raw municipal wastewater taken from the existing ABR in Kampong Bareng, Malang (Indonesia) used to feed the lab-scale of the ABR lamella. The experiment was conducted in two months and the sample of raw and treated wastewater collected from the ABR lamella for ten times from September to October 2018. The samples were taken from the inlet, lamella compartment, and the outlet. The results showed that the addition of lamella reduced the concentration of TSS and BOD for 95% and 90% respectively. While these results could help further reduction of organic and solids particle of wastewater that meet the treated wastewater regulation. The concentration of TSS and BOD as treated wastewater were 19 mg/L and 18 mg/L respectively. Although the ABR could reduce the nutrient concentration, the level still higher than the global standard for N and P.