bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of the pumping process on the properties of lightweight concrete
Authors: Arkhipkina O , Schuler B , Stipetic M 
Published: October 2019

Abstract
The distinctive characteristic of lightweight concrete lies in its combination of load-bearing and insulating properties. In order to produce this material using modern manufacturing processes such as spraying or printing, certain hurdles must be overcome. For example, a multi-component concrete has to be developed that is not only optimized concerning its rheological properties, but also takes into account the influence of the pumping process on its characteristics. Especially concerning the objective of a heat-insulating concrete, the pumping process has a decisive influence on the range of properties. For pumping applications, the system technology limits the largest grain size of the concrete mixture. This leads to very fine concretes or mortars, which react sensitively to the applied pressure. The occurring pressure-induced compaction leads to an increase in strength due to an increment in bulk density and the damage of lightweight aggregates. This, in turn, affects the thermal conductivity of the material. Based on a lightweight concrete developed at the Institute of Construction Materials at the University of Stuttgart, these challenges are highlighted and discussed in the following paper. The concrete was utilized for pumping and spraying experiments at a testing facility in collaboration with the Institute for System Dynamics, and the resulting thermal properties were examined at the Material Testing Institute, University of Stuttgart. Furthermore, the interaction between the employed system technology and the properties of the pumped lightweight concrete, such as consistency, strength, bulk density, and thermal conductivity was examined and analyzed. Results showed that the concrete properties reacted sensitively to different configuration setups of the pumping system and the conveyance line. Hence, a clear interdependency between the mix design and the employed machinery could be observed and has to be considered in future endeavours.
Using calcium chloride as an accelerator for Portland pozzolan cement concrete compressive strength development
Authors: Salain I M A K 
Published: October 2019

Abstract
The influence of calcium chloride (CaCl2) as an accelerator for the compressive strength development of concrete made with type I Portland pozzolan cement (PPC) as a hydraulic binder has been investigated. Natural sand and crushed stone were used as fine aggregate and coarse aggregate, respectively. The mix proportion of concrete, by weight, was 1.0 binder: 2.1 fine aggregate: 3.4 coarse aggregate and the water-binder ratio was 0.57. The calcium chloride added to the concrete mixture was 0%, 1.0%, 1.5%, and 2.0% by binder weight. The compressive strength test was performed at 1, 3, 7, 28, and 90 days. The test results show that adding CaCl2 to a concrete mixture accelerates the development of compressive strength. The compressive strength gain was about 36–48% at 1 day and about 29–33% at 3 days, compared to control concrete. Moreover, it increases the compressive strength of PPC concrete about 3–16% at 28 days and about 7–19% at 90 days. The optimum dose of CaCl2 to accelerate the development of compressive strength at the early age and to produce the highest compressive strength in the long-term was about 1.5%.
Making sense of high dimensional concrete data – a statistical approach
Authors: Manoj A , Babu Narayan K S 
Published: October 2019

Abstract
Performance of concrete is dependent on a number of factors. It is difficult to understand the influence and interrelationship among these variables, when there are many. Dimensionality reduction techniques can yield the best possible data interpretation based on the variance in data, without loss of much of original information. This paper presents the application of dimensionality reduction technique for analysis of data and decision making in the field of Concrete Technology.
Benefits of greening existing buildings
Authors: Rahman M M 
Published: October 2019

Abstract
‘Greening existing buildings’ is an approach to apply the principles of green building to old and existing buildings with environment responsive and energy efficient ‘green features’ or devices, e.g. through retrofitting, as and when required. It allows considerable reduction of energy consumption and greenhouse gas emission. However, the practice is not getting momentum, especially in Brunei. A study was therefore undertaken to generate and/or gauge the awareness of ‘greening existing buildings’, through identifying and assessing the key benefits of greening existing buildings. This paper presents the outcomes of 68 responses from an ongoing questionnaire survey of mainly clients and consultants. 15 benefits were identified, with “reduced energy/electricity consumption” topping the list, and “increase in building occupancy/usage rates” at the bottom. All the 15 benefits were found to be significantly important, both in the total sample, as well as in the groups of clients and consultants, and people with or without experience of green building. The two-way grouping also revealed that the above paired groups significantly showed their importance of different benefits in the same way. The outcomes are therefore considered as a general consensus of the respondents on the benefits of greening, despite some disagreements on the relative rankings of individual benefit by different groups of respondents. The outcomes are largely similar to elsewhere, and show a general awareness of the respondents to the overall benefits of greening existing buildings. Such outcomes are expected to inspire the clients to undertake more greening projects to demonstrate proven benefits. This is expected to help wider use of greening existing buildings in Brunei and elsewhere and thereby implement sustainable development.
Relationship between the construction costs and the reliability index of quay walls
Authors: Wesstein R , de Gijt J G , Heeres O M , Roubos A A 
Published: October 2019

Abstract
Structures, such as quay walls, have to meet a particular level of safety. Consequently, in the Eurocode standards, three reliability classes are distinguished, each corresponding to a target reliability index and set of partial factors. In this study, more insight is acquired into the relationship between the quay wall’s construction costs and the associated reliability index β. It appeared that the marginal costs of safety investments of quay walls are fairly low and in the same order of magnitude of the uncertainty of the estimate of the construction costs. Hence, it seems that the current reliability classes, as defined in the Eurocode standards, are non-efficient for quay walls. In addition, this study investigates the influence of the partial factors and three failure mechanisms on the construction costs and the reliability index. It was concluded that for the considered cases, the soil’s angle of internal friction strongly influences the construction costs and the β of the quay wall. Furthermore, it follows that economic optimisation in the probabilistic design of quay walls is possible by increasing the target reliability index of the failure mechanism ‘insufficient passive soil resistance’ and decrease the target reliability index of ‘yielding of sheet pile profile’.
The comparison of adding fly ash and Sinabung ash to limestone towards the soil improvement via CBR value
Authors: Hastuty I P , Roesyanto  , Rahman A F 
Published: October 2019

Abstract
Fly ash is categorized as pollutant produced from coal combustion, where the waste produced is around 4% of the total coal usage. This will be extremely dangerous since this waste is produced continuously. Mount Sinabung, which is located in North Sumatera, Indonesia, has erupted since 2010 and released a lot of ash pollution. Sinabung and fly ash can cause environmental and health problems for the people who live near the area. In the other hand, limestone is one of the building materials that can be used for soil improvement. When limestone with clay minerals reacts, it forms a strong and hard gel namely calcium silicate which can coat and bind clay particles and close the pore pores, so that it can reduce the soil plasticity index. This research analyzes the optimum CBR value and the optimum mixture. Variation of the mixture used was 2% and 4% limestone with the addition of 2%, 4%, 6%, 8%, 10%, 12% and 14% fly ash and 2% and 4% limestone with the addition of 2%, 4%, 6 %, 8%, 10%, 12% and 14% of Sinabung ash. The result shows that the mixture of limestone and Sinabung ash indicates the bigger value of CBR compared to the limestone and fly ash mixture. Furthermore, the largest CBR value was found in the mixture of 2% limestone and 8% Sinabung ash with 9.01%.
The shear strength alteration on clay soil considering the plasticity index and the percentage of fine aggregates in tropical climate regions
Authors: Tjandra D , Wulandari P S 
Published: October 2019

Abstract
Seasonal changes in tropical regions could cause variations of soil water content, especially in clay soil. Furthermore, there is a significance difference in shear strength between wet and dry clay soil which depends on the plasticity index and the percentage of fine aggregates. Laboratory experiments were conducted to investigate the effect of the plasticity index and the percentage of fine aggregates in clay soil on soil shear strength changes due to water content variation. Soil samples were obtained from five locations in Surabaya City, Indonesia. The soil characteristics were tested in a laboratory to obtain the initial water content, Atterberg limits, specific gravity, and soil size distribution. The next stage was drying the soil samples. Each one was stored at room temperature to reach the determined soil weight. The shear strength of the soil in initial and drying conditions was determined by an unconfined compression test. The results indicated that the lower the moisture contents of soil, the greater the shear strength of soil, and vice versa. Soil shear strength changes up to 52 times within the range of 36% to 72% of moisture content The results also show that the value of shear strength variation depends on the plasticity index and the percentage of fine aggregate.
Effect of adding nano-calcined clay and nano-lime on the geotechnical properties of expansive clayey soil
Authors: al-Swaidani A M , Hammoud I , al-Ghuraibi I , Meziab A 
Published: October 2019

AbstractThe objective of this paper is to investigate the effect of nano-calcined clay (NCC) and nano-lime (NL) on some engineering properties of the expansive clayey soil. Three soil samples quarried from three different sites in the south of Syria have been investigated. They were thermally treated up to three different levels (450, 650 and 850°C) for 3 hours. Then, they were ground to have a particle size of less than 100 nano-meter. Three replacement levels of NCC were used, i.e. 0%, 1% and 2%. XRD technique has been employed to detect the phases occurring in the clayey samples before and after the thermal treatment. Pozzolanic activity of the calcined clayey soil has been studied using the modified Chapelle test. Atterberg limits, compaction, free swell, swelling pressure, linear shrinkage, shear strength and CBR have particularly been investigated. Test results revealed the positive effect of NCC. Plasticity index (PI) was reduced by more than 50% when 2% NCC was added to the natural soil. In addition, 0.6% NL was added to further investigate the combined effect of NL and NCC on the properties of the clayey soil. All investigated properties were significantly improved when NCC and NL were added together, i.e. swelling pressure and linear shrinkage values were reduced to less than 15% when compared with those of the natural soil.
Thermal flow simulation for an energy garden building block
Authors: Ramadan Z , Garrecht H 
Published: October 2019

Abstract
Since energy-efficient construction is of great importance, new construction and rehabilitation methods concerning this topic will always be researched. Among these are of course, methods that benefit from solar energy. As part of the BMWi project (Federal Ministry of Economics and Energy) “SWIVT” several options of the energy consumption of residential building blocks will be explored. One of approaches to reduce the energy consumption of the building block and additionally to achieve the energy gain through the solar radiation is an energy garden building block (glass porch). The impact of this energy garden is depicted by means of CFD-simulations (Computational Fluid Dynamics) and will be analyzed in the paper [1]. For this purpose, an energy garden was modeled using an architect drawing and simulated in both winter and summer load cases. For the winter case, the difference in energy consumption between the glass porch and the thermal insulation composite system (ETICS) will be discussed based on the results of the simulation. For the summer, the heat generated by solar radiation in the energy garden can be utilized with the help of a heat pump.
Structural system identification of plane frames based on frequency domain decomposition-natural excitation technique (FDD-NExT)
Authors: Frans R , Arfiadi Y 
Published: October 2019

Abstract
Nowadays, system identification of structures has become an important subject in the civil engineering community. The reason is that with a good system identification method, modal parameters such as natural frequencies, mode shapes, and damping ratios can be obtained accurately, leading to an excellent structural health monitoring system. The two systems identification techniques are categorized as frequency-based and time-based domain identifications. In addition, the identifications based on the output-only measurements are gaining more attention from the researchers recently. One of the advantages of this type of identification is that the modal parameters can be obtained without knowing the excitation forces. In other words, it is not necessary to know the input load of the structures. This paper considers output-only identification based on Frequency Domain Decomposition (FDD) and Natural Excitation Technique (NExT) as FDD-NExt. FDD is one of the methods that relies on the output-only measurements such as displacement, velocity, or acceleration, in order to obtain the natural frequencies and mode shapes of the structures. On the other hand, NExT has good ability for determining the damping ratios of structures. This paper aims to apply the FDD-NExT to obtain the modal parameters and the damping ratio of plane frame structures. Two plane frame structures are considered in this paper to show the ability of the proposed method to predict modal parameters and the damping ratio of the structures. The first structure is a one-story frame with 6 degrees of freedom, while the second structure is a four-story frame structure with 48 degrees of freedom. For comparison, Modal Assurance Criterion (MAC) has been used to determine the difference between the modal parameters obtained by FDD and finite element analysis. The results show a good correlation between those two methods.
Dynamic behaviour of stiffened orthotropic plates subjected to Friedlander blast load
Authors: Alisjahbana S W , Alisjahbana I , Gan B S , Safrilah  , Putra J C P 
Published: October 2019

Abstract
The increase in the number of terrorist attacks have shown that the effect of blast loads, such as the Friedlander blast load on elements of a building structure is a serious matter. Their effects on the structure should be taken into consideration in the design of the structure’s element. The objective of this study is to numerically analyze the blasting effect on stiffened orthotropic concrete plates within the elastic range of its material. The effects of the stiffener configuration, the location of the localized blast load as well as the influence of the thickness to the vertical deflection of the plate are solved numerically by using the two auxiliary equations in the x and y-directions. The analysis yields the vertical deflection versus time relationship which can be used to determine the stress distributions and the maximum stress value of the plate. This paper introduces the effect of the blast load on the orthotropic plates and essential techniques used to increase the capacity of a structure’s element to provide protection against explosive effects.
Seismic performance analysis of multi-story RC frames strengthened with RC infill wall
Authors: Sukrawa M , Putra I G A K , Budiwati I A M , Salain I M A K , Susila G A , Pringgana G 
Published: October 2019

Abstract
Seismic performance of RC frame structures was investigated by creating 3-D models of the frame with additional solid RC infill wall along the height of Honolulu Building prescribed in FEMA design examples. Layered-shell element (LSE) was used to model the infill wall and gap element was introduced at the interface between the wall and the bounding frames. The modelling technique was validated against test results reported in the literature prior to its application on the 12 story building. The push over curves of all models were compared to obtain the most efficient model that conform to the strength and stiffness requirement of the seismic codes of Indonesia. The results showed that the non-linear behaviour of RC frame with RC infill wall can be modelled accurately using LSE and gap element. The RC wall addition improved the strength, stiffness and performance of the frame significantly. The most efficient model was that with infill wall up to the first 4 story levels in which, the performance of the structure improved from collapse prevention to immediate occupancy.
Structural behaviour of Reinforced Concrete (RC) columns under fire
Authors: Lakhani H , Ožbolt J 
Published: October 2019

Abstract
The paper presents a numerical study on the response of RC columns under fire. The numerical studies deal with both: during fire (fire rating) scenario and after fire (residual) scenario. The results highlight the importance of Load-Induced-Thermal-Strains (LITS) for predicting the Fire Rating (FR) of RC columns. The predicted temperature variation across the cross-section and axial deformation of column with time are in good agreement with the experimental measurements available in literature. The importance of considering cooling phase of fire for evaluating the behaviour of RC columns has been emphasized. Because of the peak temperatures occurring during the cooling phase and the additional damage due to cooling, the column may also fail during cooling period. The effect of exposure duration on the residual axial load carrying capacity of RC columns has also been discussed. The presented numerical studies using 3D fully-coupled thermo-mechanical model for simulating the behaviour of axially loaded RC columns during the complete fire hazard situation, shows its capabilities to realistically account for different strain components and damage components occurring during different phases of fire hazard (viz. heating-phase, cooling-phase & residual-state). The model uses temperature dependent microplane model for concrete and classical von-Mises plasticity models for reinforcing steel.
Tension and shear performance of anchor channels with channel bolts cast in Fibre Reinforced Concrete (FRC)
Authors: Mahrenholtz C , Ayoubi M , Müller S , Bachschmid S 
Published: October 2019

Abstract
The available design rules for anchor channels with channel bolts were developed on the basis of the design rules for fasteners installed in conventional concrete. Recently, also more advanced reinforced concrete types became popular, e.g. fibre reinforced concrete for the production of prefabricated tunnel elements. The existing design rules for fasteners including anchor channels with channel bolts do not cover fibre reinforced concrete. To study the load-displacement behaviour in tension and shear, exploratory tests have been carried out on anchor channel-channel bolt-systems cast in plain and fibre reinforced concrete. The test results demonstrate a superior performance of channel bolts installed in anchor channels which were cast in fibre reinforced concrete if compared with systems cast in plain reinforced concrete.
Crack intensity of the damaged RC beam repaired with epoxy injection using acoustic emission technique
Authors: Soffian Noor M N , Noorsuhada M N , Nizam K , M Ariffaizad M M , Noorhazlinda A R 
Published: October 2019

Abstract
This paper presents the intensity crack zones of a damaged reinforced concrete (RC) beam with the size of 200 mm x 300 mm x 1500 mm repaired with an epoxy injection under monotonic loading. The acoustic emission (AE) technique concurrent with three-point loading was used to monitor the behaviour of the beam. The intensity analysis based on AE signal strength was carried out on CH6 and CH7 at each crack mode. It was found that the intensity plots are well matched with the progression of the crack in the beam. It is inferred that the intensity zones can be utilised to characterise the damage in the beam.
Seismic hazard analysis for East Malaysia; based on a proposed ground motion prediction equation
Authors: Harith N S H , Tongkul F , Adnan A , Shoushtari A V 
Published: October 2019

Abstract
The seismic hazard analysis requires an estimation of ground motion intensity where the process needs to use a compatible ground motion prediction equation or GMPE, which provides ground acceleration estimates in a function of earthquake magnitude and distance. Hence, the effect of current equation often does not accurately represent the earthquake condition in East Malaysia region. In this study, the characteristics of low-to-moderate databases were used and derived by regression analysis in terms of horizontal peak ground acceleration (PGA). The appropriate GMPE design for East Malaysia is based on the ground motion records compiled from strike slip earthquakes that occurred within 10 to 1,350 km. This earthquake data is based on actual data recorded at a broad range of magnitude levels within a wide range of distances. The new equation is used to predict the PGA value throughout East Malaysia by probabilistic method. PSHA is a method to analyse seismic hazard assessment using probability concept by considering the uncertainties of the size, location and rate of occurrence of earthquake and the variation of ground motion characteristics. The four well-known existing attenuation functions are evaluated with current equation to highlight their limitations in magnitude and distance. With a more complete collection of earthquake databases, GMPE has become more reliable. The GMPE of peak ground acceleration for low-to-moderate earthquake at long distance was found to be logarithmically distributed. The equation provides ease in both implementation and interpretation of physical parameters with a comparable standard deviation.