bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on the Influence of Specific Factors on the Compressive Strength of Recycled Fine Aggregate Concrete
Authors: Hu Jian , He Xinshan , Li Qingbo , Bai Shaoxiong
Published: September 2019

In this test, the waste concrete is pulverized, and the particles of appropriate diameter are selected as the recycled fine aggregate to replace the natural fine aggregate. Meanwhile, the test materials are processed in different ways, and are finally made into recycled concrete. The processing methods of test materials include: high temperature treatment of concrete particles, partial replacement of cement with fly ash, and replacement of water with sodium silicate solution. To process the materials is to study the influence of its single factor or the multiple coexistent factors on the compressive strength of recycled concrete, and then to explore the most effective method of recycled fine aggregate use under preset conditions. The results show that: 1) When the natural fine aggregate is replaced with the recycled fine aggregate and there is only a single variable factors, the compressive strength of the recycled concrete increase most obviously after the concrete particles are processed through a six-hour-long high temperature heat at 300°C, and when the replacement rate of recycled fine aggregate is about 35%, the strength value is the maximum; 2) When there are multiple variable factors in the test, the compressive strength of the recycled concrete is lower than that of the single variable factors.
Study on Physical and Mechanical Properties of New Self-insulated Block
Authors: Bai Ling , Fang Guangxiu
Published: September 2019

This paper has developed a dumbbell-shaped self-insulated block with recycled ceramsite concrete as the main body and filled with recycled foam concrete. Through the physical and mechanical properties test, it is concluded that the performance of the block is better than the specification requirements and can be used as a load-bearing block. According to the test results and the normative formula, the correction coefficient of the relationship between the block and the concrete cube is obtained.
Effect of Temperature on Micromechanical Properties of Pol-yvinyl Alcohol Fiber–Matrix interface and Uniaxial Tensile Properties of High-Ductility Cementitious Composites
Authors: Guo Li-ping , Yang Ya’nan , Chen Bo
Published: September 2019

This study investigated the effects of temperature on the tensile strength of polyvinyl alcohol (PVA) fibers, micromechanical properties of the fiber–matrix interface, and macroscopic uniaxial tensile properties of high-ductility cementitious composites (HDCC). In particular, the following values of the temperature of different regions and the glass transition temperature of PVA fibers were selected: –30 °C, 0 °C, 20 °C, 60 °C, and 180 °C. Thermogravi-metric analysis and differential scanning calorimetry of PVA fibers were carried out using a synchronous thermal analyzer. In addition, the micromorphology of failure fibers and the fiber–matrix interface was observed using a scanning electron microscope. The results showed that when taking the tensile strength at 20 °C as a reference value, after heat treatment at –30 °C, 0 °C, 60 °C, and 180 °C, the average tensile strength of PVA fibers was 86%, 89%, 88%, and 60% of that at 20 °C, respectively. The ultimate tensile strain value of HDCC was closely related to the treatment temperature: it was the largest at 0 °C; its values at –30 °C and 60 °C were essentially equivalent, its value at 20 °C was small, and its value was the smallest at 180 °C. It can be concluded that after the heat treatment, the tensile strength of PVA fibers decreases to some extent, and there is a piecewise linear relationship between the fiber tensile strength and temperature. Hence, an appropriate heat treatment can reduce the chemical debonding energy and increase the frictional bond strength at the onset of fiber slippage. At the same time, the effect of temperature on the ultimate tensile strain of HDCC is opposite to that on the chemical debonding energy of the fiber–matrix interface.
Chemical Kinetics Analysis of Strength Development of Mortar Containing Fly Ash Based on Various Curing Temperatures
Authors: Ning Fengwei , Bai Yin , Chen Bo , Ding Jiantong , Zhang Feng , Lv Lele
Published: September 2019

Due to large size and high internal temperature of hydraulic dams, the strength development process of damming materials is often faster than those under standard curing conditions. In order to further study the strength development features of damming materials under internal temperature conditions, two kinds of fly ash mortars were investigated, of which fly ash content is 40% and 30%. The compressive strength of mortars under three curing temperatures containing 20, 30 and 38°C was tested at 3 days, 7 days, 14 days, 28 days, 56 days and 90 days, respectively. Then chemical kinetics equation was employed to describe the strength development features under different temperature conditions. The results show that the compressive strength of fly ash mortar increases with the increase of curing temperature in the range of 20 to 38 °C. The main reason is that the chemical reaction rate of cementitious materials is accelerated by increasing curing temperature. For example, the hydration rate at 30° is 1.6 to 1.9 times of that at 20°, and the hydration rate at 38° is 3.1 to 3.9 times of that at 20°. In addition, the hydration rate of mortar with higher fly ash content is accelerated more. It can be seen that the apparent activation energy of mortar containing 40% of fly ash is 1.2 times of that with 30% of fly ash, and its chemical reaction barrier is higher. Therefore, the equivalent age of mortar with 40% of fly ash is longer and its compressive strength is improved more greatly under temperature-raising conditions.
Elastic Properties of the Remolded Soil During Freezing and Thawing Cycle By Bender Elements
Authors: Zheng Yonglai , Pan Tanbo , Zhou Yubao , Özselek Burcu
Published: September 2019

The elastic properties such as shear moduli and shear moduli of freezing and thawing soil are important parameters for analyzing the stress distribution and thaw-subsidence of freezing soil and deformation of well casing embedded in freezing soil. This paper presents elastic properties obtained by conducting laboratory testing of sand samples from the area of soil. The bending elements were used to measure the shear wave (S-wave) velocities for evaluating the shear moduli during freezing and thawing. Nine pairs of testing specimens were conditioned from 25°C to -25 °C at an interval of 5 °C for examining the temperature effects during freezing and thawing process, respectively. The test parameters included dry density (1.6,1.8,2.0 g/cm3) and moisture content(6%,9%,the saturation). Test results showed that the wave velocities and the shear moduli in all types of specimens tested exhibit sharp change when the temperature adjacent to 0 °C, likely due to non-uniform freezing point depression caused by the varying structure among specimens. The increase of dry density has positive effect on shear modulus. However, the moisture content has a dual effect on the strength of the sand soil.
Research on microscopic features of salt rock being damaged via loading osmosis on the basis of CT scanning
Authors: Zeng Yin , Liu Jianfeng , Li Zhicheng , Xu Huining , Wang Lu , Zhang Qiangxing
Published: September 2019

In order to study the microscopic characteristics of the salt rock being damaged through diverse level of osmosis, CT scans are made to the salt rock before the osmosis loading and after it is damaged, in which the stress-strain is applied to the whole process. The differences of the micro-features of damaged salt rock are discussed. The experimental results show that: (1) the microscopic characteristics observed from CT scan indicate that the critical confining pressure of salt rock is 10MPa. When the confining pressure is lower than 10 MPa, shear crack can be seen obviously in the cross and longitudinal section of the salt rock, with the form of shear damage; While confining pressure is more than 10MPa, the fissure is short and the rock is damaged in a drum-shaped deformation; An impervious point occurs when it exceeds 10MPa. (2) The number of cracks demonstrates the intrinsic crack development of salt rock. The salt rock has a critical point (d=0.6mm) in the number of small cracks (d≤1mm). 0.6mm is the boundary point. When it is 0.6mm or less, the number of fissures in the salt rock with confining pressure of 5MPa is more than those with 10MPa. The larger the diameter of the fissure is, the closer the number of fissures with the above two confining pressures is. While boundary point is more than 0.6mm, it will have the opposite effect. (3) The internal mechanism of that the end effect has an impact on the osmosis evolution of salt rock is uncovered. Due to the stress-intensive effect at the ends, the development path of the small cracks gradually spreads from the both ends to the inside, therefore, the osmosis of the gas osmosis channels at the ends is hindered, resulting in a low salt rock permeability during the loading process.
The Durability and Performance Test methods of the New Type of Pavement Filling Material - An Holistic Review
Authors: Liu Gaojie , Bai Erlei , Xu Jinyu , Wang Tengjiao , Chang Sen
Published: September 2019

Airport pavement joint weaknesses are one of the important factors that affect airport performance and threaten flight safety. The traditional pavement caulking materials are mainly asphalt-based materials of heating construction type, which are prone to aging, loss of adhesion and other shortcomings in natural environment. Based on the shortcomings of traditional pavement caulking materials, this paper introduces the research and application status of new type of filling caulking materials represented by high-performance elastic polymer materials, with emphasis on its durability, performance testing methods. Finally, it summarizes the existing problems and prospects of the new type of pavement filling caulking materials.
The influence of the warm-mixed agent on the performance of Gussasphalt after superheated aging
Authors: Huang Wenhong , Sun Mingzhi , Qin Yunjie
Published: September 2019

Gussasphalt has been widely used in steel bridge deck and pavement in China, but it will lead to the pyrolysis aging of gussasphalt binder in the mixing process due to the high temperature and longtime mixing. The effect of improving the aging performance of Gussasphalt was studied by adding warm-mixed agent after superheat aging, and the aging performance between the matrix asphalt and the gussasphalt modified with Sasobit and RH were compared and analyzed. The results show that: RH warm-mixed agent has little effect on the penetration of Gussasphalt binder, while Sasobit warm-mixed agent has more influence on the penetration of Gussasphalt binder. Gussasphalt binder with of 2% RH warm-mixed agent or 1% Sasobit warm-mixed agent is the optimum mix dosage. The adding of 2% RH warm-mixed agent or 1% Sasobit warm-mixed agent can effectively decrease the mixing temperature of the mixture, and Sasobit’s effect is better.
Road performance of tourmaline/rubber powder modified asphalt mixture
Authors: Fu Hao , Chen Qian , Song Zhi , Xiao Xudang , Fan Zhentong
Published: September 2019

To study the effects of tourmaline type and content on the road performance of rubber powder modified asphalt mixture, different types of tourmaline rubber powder modified asphalt mixtures were prepared by adding tourmaline powder instead of equal weight mineral filler into the mixtures. Based on indoor simulation test, the high temperature stability, low temperature crack resistance and water stability of rubber powder modified asphalt mixture under different tourmaline type and content were systematically analyzed. The results show that with the increase of tourmaline powder content, the road performance of asphalt mixtures show an overall growth trend. The 60 °C of rutting test dynamic stability, the -10 °C of bending test flexural-tensile strain, immersion residual Marshall stability and freeze-thaw splitting tensile strength ratio of rubber powder modified asphalt mixtures with tourmaline powder increase by 12.5-19.6%, 7.5-12%, 1.8-4.7% and 1.7-4.3%, respectively.
Social Significance of Technical Water Purification and Treatment Plants – on the Cusp of New Functions of the technical Service Buildings of Cities
Authors: Wojtowicz-Wrobel Agnieszka
Published: September 2019

Departure from environmentally unfriendly public attitudes and the increasing awareness of environmental protection and the management of natural resources among the residents of cities lead to pro-environmental design efforts—including planning and urban-design-related ones, for the shaping of urban structures. One of the elements of cities that, on the one hand, stir public emotions and on the other constitute an inseparable element of the urban organism, are structures that provide technical services to cities. Examples of these structures include wastewater treatment and water purification plants. The goal of this article is an attempt at finding an answer to the question about what role do wastewater treatment and water purification plants currently play in the structure of Polish cities and what other roles can they play. Particular emphasis was placed on the public reception of such structures. Based on Polish cases, this reception appears to most often be either neutral or negative. The author explores the mechanism of these reactions and their causes, particularly in reference to other structures that provide technical services to cities (e.g. eco-incineration plants, whose construction is faced with intense opposition from residents in Polish conditions almost every time). The author searches for an answer to the question about the cause of public opposition to the construction of these types of structures, and whether we can—and if so, then how—prevent such public attitudes in relation to these types of structures.
Ecological Urban Agriculture from the Point of View Basic Elements of Sustainability
Authors: Posivakova Terezia , Svajlenka Jozef , Hromada Rudolf , Korim Peter
Published: September 2019

Population grows fastest in the world’s urban and metropolitan cities, the number of inhabitants in so-called metropolitan cities and in urban and suburban zones are expanding into the surrounding natural landscape. Consequence of these changes is the gradual displacement of natural greenery and nature from cities and newly created residential satellites designed to build residential and public amenities. In recent years, is more commonly used sustainable development phenomenon which has become as a responding trend to of cities and municipalities and the implementation of so-called urban gardens intended for growing crops within the communities of the population. In view of mentioned facts the presented article focuses on ecological urban agriculture in terms of the main components of sustainability as an element contributing to the sustainable development of cities and suburban zones.
Spatial Memory: A Childhood House a Proposed Model of the Memory and Architecture Relationship
Authors: Ozak Nilufer , Pulat Gokmen Gulcin
Published: September 2019

This paper has been shaped and developed on the proposition that a relationship exists between memory and architecture. The mechanics of memory have been studied for many years by various disciplines and its connection with architecture, either individual or collective, forms the spatial memory in architecture. In the formation of this spatial memory, the interaction with one’s environment and the memory of this interaction stored in one’s brain makes the ability to remember and recall the important. Consciously, what significance do people attribute to remembered spaces? How do they value them, in their own words? How do the remembered spaces interact with them? Can spatial memory emerge and bring new values to architecture? This study aims to investigate the importance of the formation of spatial memory in an individual’s dynamic relationship with any particular space. A “Childhood House” has been selected as the space for the study. There are many scholarly books that address the space of the house where it has been a particular focus from a memory point such that it collects an individual’s past relationship with the space. The recollection of the childhood house by an individual relates the spatial relationship one has with memories of the past. Spatial memory, which has been formed on concepts of memory, perception and this house, is analysed in a proposed model aimed at explaining what spatial elements might be the inputs in forming spatial memory. Individual features, the social environment of the era and physical characteristics of the space are selected as the main features to form the spatial memory of a childhood house. The model also puts forward several sub-features which enhance the recall moment of an individual when interacting with a space. Main and sub-feature inputs of the model form multi-layered spatial memory outputs which show the brain’s ability to code, store and recall. Twenty individuals were chosen to contribute to the study, using their recall of childhood house memories to respond to pre-set memory/space related questions. Each individual’s spatial recall verified that the proposed memory/space relationship model showed clear evidence that the spatial memory is formed under the influence of these three important characteristics: Individual, social/cultural and physical interaction act in concert to constitute a spatial memory.
Heterotopic Urban [A]Destinations
Authors: Guatelli Igor
Published: September 2019

Different from the Utopias, normally treated as a unique projection of an ideal future, despite their multivalent potentiality of refusal, the heterotopies are always plural, multiple unique places in their existences; places at the margin of universal and universalizing logics. The term is connected to one of the discussions held by Foucault [1] on the existence of unique spaces, which dispositions in the society transform them in deviant or diachronic spaces in relation to the cultures, in which they are inserted. They are spaces administrated and managed according to quite specific laws, on the one hand, inverted images of the logic to which they belong or which they reflect; spatial differentiations resulting from the social realities and logics of which they are repressed and begin to illustrate in an inverted manner and, on the other hand, they take on the role and the chance to be spaces with a onto-teleologic dimension (existence and purpose) that may be disturbed by temporary situations capable of introducing other impermanent operating logics (events of heterochrony). Which were the logics that came as social and spatial becoming “with” the heterotopics places: The Viaduc des Arts in Paris, the Spitellau Viaduct in Wien, the High Line Park in New York and the still “hesitant” transformation of Elevado João Goulart, in São Paulo, into a park? Which infrastructural spectra are those which, when they return as antagonists of what they were or what they insist on being, deflagrate other sociabilities? What was expropriated from these infrastructures at the moment they returned and return, and are socially re-appropriated, according to another city-planning logic? What is in front of us and what is still to be seen as an urban and social phenomenon? This entity that returns is edited by visible and spectral forces, invisible, or by what is apparently beyond and beneath the thing, surrounding it, underlaying it but, even so and despite of it, already is or still is the thing itself.
Glass Fins – A Structural and Aesthetical Application in Glass Facades
Authors: Brzezicki Marcin
Published: September 2019

The use of glass fins constitutes a recently emerging trend in the façade industry. Fins (ribs) could be defined as long glass strips mounted perpendicularly to the surface of the façade. Fins are used as (i) decorative (aesthetical enrichment of the facade), (ii) functional (sunshade) and (iii) structural (stiffening and load-bearing) elements of the facade. The overall trend of using glass fins is a result of the abundance of proper quality glass, that allows for safe use of relatively small elements that are point mounted or fixed in a different way to the surface of the facade. This glass fin trend deserves a review, illustrated with the on-site made photographs showing different areas of application. The given review of the application of glass fins is based on a general morphology study of transparent facades that the author conducted through the year 2017-2019, and including the position of the fin, the orientation of the fin, and the transmissive qualities of the fin – transparent, translucent and screen-printed. Fins could be also addressed as a formal articulation element strategic from the point of the building’s architectural form.
Effect of Central Pedestrian Refuges on Calming of Traffic in Their Vicinity
Authors: Solowczuk Alicja , Kacprzak Dominik
Published: September 2019

Central pedestrian refuges are one of the traffic calming measures used in small towns and villages located on through routes. Their main function is to protect vulnerable road users from safety hazards and reduce the 85th percentile speed v
85 before the island. In order to determine the efficiency of the central refuges in obtaining reduction of v
85 speed to the desired level before the islands the authors measured the speeds both before and after the islands of different width in specific locations along the stretch i.e. in the entry, central and in the exit zones. The central refuges were typically 2 m wide, imposing a 1 m deflection of vehicles. Other deflections, namely by 2.5 m and 3 m were imposed by two of the analysed islands. In one case the vehicle path was not deflected, namely at the refuge/chicane combination located on the departure lane. The research covered in total ten different cases of crossings in villages on regional roads. Most of the analysed pedestrian islands were accompanied with hatched areas before and after the island with a conventional 1:5 taper. All the islands are located in a residential areas, yet with different types of adjacent developments. In all the analysed cases the maximum permitted speed during daytime was 50 km/h. Speed measurements were carried out with special traffic detection devices equipped with automatic traffic speed and volume recording function. The analyses considered free-flow average and v
85 speeds. In a few cases buildings were located close to the roadway edge right after the central refuge. In the other cases the road was surrounded by a rural area or a forest. In two cases the island was followed by a horizontal curve affecting the sight line. The desired speed reduction or reduction down to the statutory speed for residential areas before the island was not obtained in all the analysed cases. In a few cases average speed under free-flow conditions of ca. 50 km/h and v
85 speed of 55 km/h were obtained for the islands located in the village centres with houses located close to the road edge. Without residential buildings located close to the road edge before the island and with a restricted view on the further course of the road reduction of both speeds was obtained after the island. Smaller speeds were noted also on the road sections where greater horizontal deflections were imposed. The greatest speed reduction along the island was noted on the sections with reduced visibility or with residential buildings in close proximity. The degree of deflection was found to have a smaller effect.
Safety in measurement activities of buildings done with different methods and equipment
Authors: Pawlowicz Joanna A.
Published: September 2019

In this chapter, methods and measurement equipment was described, which have been used by man since the beginning of history. Their accuracy and minuteness depend on the needs and goals of making measurements and the advancement of technology at the disposal of a user. The paper focuses mainly on the most modern method of building measurement i.e. laser scanning. A different aspect of making measurements with a scanning device and the principles of its safe use were presented. Building measurement activities are always connected with the risk of an accident, especially of falling from a height. The 3D laser scanner eliminates this problem, and additionally, we get a result which surpasses the accuracy of other described methods.
Barracks from Modern Age Iberian Wars (1650-1750) Heritage Value, Contemporary Use and Social Housing
Authors: Costa Rosado Ana , Navas-Carrillo Daniel , Lopez-Bravo Celia , Perez-Cano Teresa
Published: September 2019

The present paper studies 18th century military garrisons built in border villages of Portuguese Alentejo during the instability period that began with the Restoration War (1640-1668) between Portugal and Spain. Besides presenting their constructive types and materiality, the research focus on the heritage value of these barracks, especially given their urban context inside small peripheral towns’ historical centres under threat of desertification. Three cases are compared in order to determine which contemporary use better favours heritage conservation of the barracks modular structures.
Housing Estate Game V.2.0 - Ideas for Design of Housing Estates’ Density Models - The Case Study of Urbanism Workshops Game Created for Science Promotion
Authors: Bradecki Tomasz
Published: September 2019

The article presents the main principles of HOUSING ESTATE GAME 2.0 - a game proposed by the author for the purpose of promoting science among children and adolescents. The game allows creative implementation of residential housing models according to predetermined rules. The accepted score and rules of the game coincide with the assumptions of the compact city idea and draw attention to the problems of modern housing estate implementation. Particular attention was paid to selected urban indicators such as: housing density, the amount of biologically active area, number of trees, number of parking spaces. The principles of the game are consistent with the real-life design principles and address a true challenge: how to provide compact dense housing estate and high-quality housing environment. The game, in its current form, is the result of its several years of improvements. Version 2.0 of the game was tested during the NIGHT OF RESEARCH at the Silesian University of Technology in Gliwice, while other editions of the game were presented during the Science Festival in Katowice. The article discusses the main theoretical and methodological assumptions for the implementation of the game. The author presents both a ‘game manual’ to promote it and conclusions from the last edition of the workshop which may be useful for formulating educational assumptions about the creation of habitats. The article shows contemporary challenges in housing estates’ design, the conclusions may be useful for architects, urban designers, academics in the field of architecture and urbanism, public participation practitioners. The author is an academic researcher, an architect and a professionally active urban designer, and actively promotes science through workshops and other activities.
Determination of Profiled Sheet Metal Strength under Standard Testing Loads Using Nonlinear FEA
Authors: Vacev Todor , Milic Milos , Nesovic Ivan , Zoric Andrija
Published: September 2019

Profiled sheets are widely used in modern steel structures, either as cladding or as casing in composite structures. Their strength calculation represents a complex task because one must deal with thin-walled structures that have complicated cross-section shape. Manufacturer’s catalogues provide data about their strength, mostly for continuous surface load. These data are mostly obtained by testing. EUROCODE EN 1993-1-3, i.e., its Annex A2, regulates the testing procedures for profiled sheets, allowing two main approaches regarding load application: uniformly distributed load and equivalent line load (in four locations). In addition, the mentioned code proposes roller supports that simulate pinned joints at the ends, neglecting the fastening conditions, which unavoidably are present with these structures. Aim of this research was to prove if the two proposed load patterns produce identical results, and to reveal how fastening devices affect the structural strength. In this research, the Finite Element Method (FEM) analysis with geometrical and material nonlinearity and contact analysis in the support zones were applied for the strength calculation of one typical profiled steel sheet. The analysis was conducted for ultimate load strength and for maximum load at standard deflection of L/200. In order to provide the testing conditions as real as possible, the support conditions were set in two ways: a) with support width B=40 mm and N=2 fasteners at the support, i.e., one fastener in each outer trough; b) with support width B=200 mm and N=8 fasteners at the support, i.e., two fasteners per every trough. The first support case is intended to simulate behavior close to a simply supported beam, and the second should simulate a beam fixed at its ends. The analysis encompassed the two load patterns provided by EUROCODE standard, and the results were compared. The results reveal that the surface load approach gives higher strength values than the four-point-load, both for ultimate load and for maximum load at deflection of L/200. This stands for both analyzed support conditions. The results of the research indicate that the codes should much more precisely define the testing conditions for such structures and make them closer to reality, for the purpose of more reliable and economic design.
The Impact of Weather on Traffic Speed in Urban Area
Authors: Chmielewski Jacek , Budzynski Marcin
Published: September 2019

The issue of the impact of weather conditions on trip speed of vehicles has been studied for a long time and it is still the subject of many scientific researches. The impact of atmospheric conditions on the speed with which drivers drive their vehicles seems to be obvious. Good weather conditions, sunny weather with good visibility surely provokes higher speed while rainfall, wind and visibility limitations will force drivers to reduce speed, drive with more concentration, and be more cautious. In the light of emerging new possibilities of acquiring data on vehicle speed, especially travel speed indicating the speed of trip between designated speed measurement points using modern measurement technology new researches are possible. Increasingly in the ITS systems being implemented mainly in urban areas, ANPR (Automatic Number Plate Recognition) cameras are one of the ITS element. These cameras make it possible to determine the real time of appearance of the vehicle in the register area of the camera, thus determining both the matrix of trips between each two observation points (ANPR cameras), but also the vehicle’s ride time between successive cameras, and thus the speed of trip. In conjunction with data on weather conditions registered by several dedicated weather stations, they allow to significantly increase the research sample in terms of vehicle speed, and thus to obtain a statistically more confident inference. Thus, it gives a chance for further analysis regarding the impact of atmospheric conditions on road traffic conditions, including on travel speed and capacity of transport infrastructure. The article will present the results of empirical analyses to determine the impact of weather conditions (including temperature, ice thickness, air pressure and precipitation) on the vehicle trip speed.
Assessment of an existing prestressed concrete bridge according to the partial factor method for existing structures (fib Bulletin 80)
Authors: Gino Diego , Castaldo Paolo , Bertagnoli Gabriele , Cimetta Simone , Mancini Giuseppe
Published: September 2019

The assessment of existing reinforced concrete structures is a critical aspect for engineers and practitioners. In particular, existing infrastructures, as bridges and viaducts, are extensively exposed to environmental actions, materials aging, degradation and variation of magnitude of traffic loads during their service life. Hence, to perform the assessment of existing structural systems assuming the same criteria conceived for the design (i.e., partial factor method – EN 1990) can result to be too conservative and, sometimes, leads to unnecessary and costly structural interventions. In this context, fib Bulletin 80 defines a new partial factor method suitable for the assessment of existing reinforced concrete structures and infrastructures accounting for their residual service life, information from in situ and laboratory tests, measurements of variable actions and reduced target reliability levels according to economical and human safety criteria. The methodologies proposed in fib Bulletin 80 have been applied to the assessment of an existing precast box section pre-stressed reinforced concrete bridge built in 90s and located in north of Italy. The results are compared to the outcomes from the assessment performed according to EN1990 and, finally, limits and advantages of fib Bulletin 80 methodologies are discussed.
Comparison of Sediment Loss Modelling by Using the Physically-Based Erosion-3d Model and The USPED Empirical Model: A Case Study of the Svacenicky Creek Catchment (Slovakia)
Authors: Nemetova Zuzana , Kohnova Silvia
Published: September 2019

The study presents a validation of the physically-based EROSION-3D model and the USPED empirical model and compares them with actual measured data. During the last decade there has been an intention to develop a new generation of erosion models in order to replace the Universal Soil Loss Equation used worldwide with more effective methods. One of those methods is represented by physically-based models, which provide a tool that relies upon descriptions of the processes that occur in actual natural conditions. The essential element of physically-based models is that they are process-based and reflect the most recent advances in erosion and hydrological research. In the modelling of soil erosion, the validation and verification of the methodologies used are considered as general problems. The importance of a model´s validation can be seen in the building of confidence in the ability of the model to generate satisfactory simulation results in order to discover the strengths and weaknesses of the model used. The physically-based EROSION-3D model is suitable not only for research purposes, but also for engineering practices, e.g., for assessing the effect of changing agricultural management practices and their impact on soil losses. The validation of the models has been performed on a continuous rainfall series for the selected period 2015 - 2016. The modelled results were compared with the actual measured sediment deposition data acquired by a bathymetry survey of the Svacenicky Creek polder using the EcoMapper Autonomous Underwater Vehicle device in the same period. The Svacenicky Creek polder is a part of the flood protection measures in the investigated territory of the Myjava region in Slovakia. The final results present a comparison between the outputs from the models used together with a confrontation of the modelled and observed results obtained by the bathymetry measurements.
An Assessment of Changes in Ecological Stability and Landscape Management Practices over the Last Centuries: A Case Study from Vrbovce, Slovakia
Authors: Vyleta Roman , Valent Peter , Nemetova Zuzana , Hlavcova Kamila
Published: September 2019

The landscape is an open system influenced by natural and anthropogenic factors that in a long-run fundamentally affect its state and development. A comprehensive understanding and assessment of the anthropogenic impacts on the environment is a key prerequisite to maintain its good ecological state. However, as the impacts of anthropogenic activities on the environment are omnipresent, necessary measures for their mitigation should be addressed to improve the landscape ecological stability. In Slovakia, agricultural activities on large blocks of land are considered as one of the main anthropogenic factors negatively influencing the landscape ecological stability, which however could be eliminated by effective landscape management activities. This study assesses the ecological stability of the cadastral area of the village of Vrbovce in both historical and current contexts and suggests several “green” measures aiming at improving its ecological stability. The information about the land types and structures were obtained by manual vectorization of historical and current topographical maps. Based on this information analysis of land utilization and its development was carried out for a period of more than 250 years. For each historical period, a coefficient of ecological stability was evaluated to assign a degree of ecological stability for each period. Moreover, an analysis of positive and negative landscape-ecological impacts was also performed to identify the problematic areas within the cadastral area that need to be addressed by mitigation measures. Based on these analyses several mitigation measures were suggested to improve the ecological stability of the area. Most of them were related to the agricultural land, which makes up a significant part of the area and represents its less ecologically stable part. The proposed measures respect the original rural character of the area and its specific scenery which is a result of centuries of man-land interaction. The measures are mostly focused on transforming some of the less ecologically stable areas into natural grasslands which would be used for ecological cattle and sheep breeding as these activities were historically the primary source of living in this area.
Modernity in architecture - Tokyo, Osaka, Dubai, Gdańsk, Katowice
Authors: Fross Klaudiusz , Guminska Anna
Published: September 2019

The article describes conducted observational studies of contemporary architectural objects in various parts of the world. Examples from Japan, the Emirates of Arabia and Poland - contemporary architecture of cities: Tokyo, Osaka, Dubai, Gdańsk, Katowice have been described. He evaluates them and draws attention to the essential elements. He conducts an original discussion on the contemporary architecture. In the subjective assessment, two elements are always important: meeting the investor’s goals and the needs of users. Observation of what is happening new in a built environment is an integral part of the architect’s work. Of course, it is good to look at new architectural realizations of buildings and examples of space management, not only superficially, e.g. in terms of the overall aesthetic image or an interesting detail, but also to make a somewhat deeper assessment. Evaluations, e.g. in terms of meeting the needs and satisfaction of users, efficiency and cost-effectiveness of solutions. In order for the assessment to be professional despite the fact that in the observational form (own observation) well as the architect knows the basics and techniques of qualitative research. Qualitative observational studies were aimed at identifying factors shaping contemporary architectural objects and the surrounding space. Due to the globalization, the scope of research has been established to be very wide, taking into account different regions and cultures. The result of the research was to identify various types of elements affecting the quality of architecture. The main elements of this analysis include adapting objects to the various needs of users and investors. The universal principles of typical solutions of the contemporary architecture related to the quality of this architecture were also defined.
Research of Behaviour of Bed Joints Reinforced Masonry Walls with Openings Made of Autoclaved Aerated Concrete under Horizontal Shearing
Authors: Jasinski Radoslaw
Published: September 2019

This article describes results from testing reinforced and unreinforced walls with openings of different shapes. Conducted tests mainly focused on determining the effect of used reinforcement on the cracking morphology and values of cracking and failure forces. Every wall was made of AAC masonry units. Tests covered 12 walls with the following external dimensions l = 4.43 m, h = 2.43 m, t = 180 mm, which varied in shape and dimensions of openings. The walls were reinforced with steel trusses of EFZ 140 / Z 140 type (Z1 type) and meshes made of plastics (Z2 type). In remaining six series, used walls (external dimensions l = 4.43 m, h = 2.43 m, t = 180 mm) with different opening shapes denoted by convention as A, B and C. Elements with A-type opening, 1.48 m wide and 0.98 m high, consisted of two models marked with the symbol HAS-AAC-Z1 (Z1 type of reinforcement) and HAS-AAC-Z2 (Z2 type of reinforcement). Elements with B-type opening, 2.66 m wide and 0.98 m high, consisted of two unreinforced models were marked with the symbol HBS-AAC-Z1 (Z1 type of reinforcement) and HBS-AAC-Z2 (Z2 type of reinforcement). The third series included a window opening with the width of 1.62 m and the height of 0.98 m, and a door opening with the width of 1.03 m and the height of 1.90 m. The arrangement of openings was denoted by convention as C. Similarly, as in case of walls with A- and B-type openings, the series of C-type opening included tests on two models marked with the symbol HCS-AAC-Z1 (Z1 type of reinforcement) and HCS-AAC-Z2 (Z2 type of reinforcement). The results were compared with test results for unreinforced walls with openings, tested under the same initial conditions. A mechanism of wall destruction, changes in cracking morphology, and values of cracking and failure stresses were analysed.
The concept of creative industries within the creative city and its implications on the quality of public space
Authors: Pieczara Marta
Published: September 2019

The goal of the presented paper is to investigate the potential positive influence that integrating the creative industries within the concept of the creative city can have on the quality of public spaces. The primary supposition is that the concerned idea can formulate an important part of the integrated urban renewal strategy, bringing a response to the declining attractiveness of city centres as well as to the growing outward migration of their inhabitants. Particularly, situating the creative industry plants within an urban context can be considered as an action that can potentially lead to the economic revival of the neglected neighbourhoods and, in consequence, can initiate their effective revitalisation process, leading to the urban landscape’s vital improvement. The concept of such a strategy constitutes of the substantive basis of the design task being commissioned to architecture students at the Poznań University of Technology within the framework of the regular training program. The exercise is to design a creative industry plant within an urban context and it has for its preliminary step to identify a district that requires modernisation. Then, by introducing the heterogeneity of both architecture and use, the students’ projects aim to diversify the functional profile of the neighbourhood as well as to create new public spaces or to revitalise existing ones. Concentrated mainly on the agglomeration of Poznan, the presented paper resumes the outcome of the concerned academic projects and investigates the prospective influence of the concept of creative industries within the creative city on the quality of the urban space.
Academic buildings as a substantial part of the teaching system. The case of the new building design at the School of Engineering, National University of Rosario, Argentina
Authors: Piacentini Ruben , Vega Marcelo , Morabito Julieta , Rene Estevez Maria
Published: September 2019

The population growth observed in the past decades demands that future buildings will have to include energy-efficiency measures as well as their own clean energy production plant, in order to be of very low or, if possible, positive net energy. This means that buildings will produce, on an annual basis, more energy than they will consume. The design of the new building for the School of Engineering, Faculty of Exact Sciences, Engineering and Surveying, National University of Rosario, Argentina, is given as an example of this kind of building. The building techniques applied in this design include: autoclaved aerated concrete in walls and insulation thermal roof panels, high energy and water consumption efficiency, photovoltaic power supply and sensors/dataloggers and actuators placed in the main equipment and sites. With these technological improvements, several analyses yielded reductions of 70%, in comparison with conventional buildings. Regarding the energy consumption of the facility, this is estimated at 29620 KWh/year, resulting in an energy intensity of about 25.7 KWh/(m2year). The energy annually produced by the PV plant (58491 KWh/year) exceeds what is required, which makes the facility a positive energy building in +49.4%, being this surplus exported to the National Electrical Interconnected System. The positive (clean) energy building implies that it avoids the emission to the atmosphere of a given quantity of greenhouse gases, in the present case 20647 TnCO2eq. In this way, through a comprehensive design of buildings, the construction sector can collaborate on the global contamination reduction and, consequently, global warming mitigation.
Aesthetic Delirious Urbanism – Rem Koolhaas
Authors: Lacerda Neto Filipe
Published: September 2019

According to Rem Koolhaas, the ’70s had a great impact on the western economic life. It was the beginning of two twin systems: financial and political, the liberalism and the globalisation. During this decade, New York is the stage of the decaying show of organised crime, drugs and social and financial crisis. In 1977, in an attempt to save the city, the campaign “I ♥ NY” is launched. It emphasises the possibilities of New York´s urban and frenetic life. The city proclaims itself as the centre of the world, at least of the western world. As a consequence, driven by a blind patriotism, or even delirious, Manhattan´s architects took possession of the most obvious characteristics of the city´s architecture of the period before the Second World War. A new old city develops. According to Rem Koolhaas, it is an architecture made of money “shots”. In 1978, Koolhaas publishes his retroactive manifesto “Delirious New York”, where, in due course, he draws attention to the constant relation between the city and the new all over the centuries. In this manifesto, Koolhaas reveals his fascination with the modernity and urbanity. His work depicts Manhattan’s evolution since its “Prehistory” – before the European’s occupation – as an experience of modernity. An island that is a pioneer in the problems that affect the main capitals of the world today, but also a pioneer in the attempts of solving, or at least maintaining, the chaos that it contains. The aim of this written essay is to analyse and clarify how the fascination with the new technology, and the way this relates to what is banal – urban – delirium – represent aesthetic criteria in Koolhaas’s work.