Current Issue : October - December Volume : 2018 Issue Number : 4 Articles : 6 Articles
No-fines lightweight concrete wall with horizontal reinforcement refers to an alternative\nmaterial for wall construction with an aim of improving the wall quality towards horizontal loads.\nThis study is focused on artificial neural network (ANN) application to predicting the deflection\ndeformation caused by dynamic loads. The ANN method is able to capture the complex interactions\namong input/output variables in a system without any knowledge of interaction nature and without\nany explicit assumption to model form. This paper explains the existing data research, data selection\nand process of ANN modelling training process and validation. The results of this research show\nthat the deformation can be predicted more accurately, simply and quickly due to the alternating\nhorizontal loads....
Building energy conservation measure (ECM) of insulation materials suitable for the domestic situation in the construction\nsector (passive) is established. The ECMs of insulation materials were classified into walls, roofs, and floors. Also,\neconomic evaluation databases, which are composed of material costs, labor costs, and expenses for constructed alternatives,\nwere built. After setting the target building and deriving the ECM list of insulation materials for the target\nbuilding, the energy use evaluation and economic evaluation were performed for each constructed alternative. Based on\nthis, the optimal building energy conservation measure of the target building was derived by applying the decisionsupport\nprocess....
Concrete is the most widely used for construction materials in the world. Water\ncontent of concrete is an important parameter in terms durability of concrete\nstructures. Terahertz (THz) waves, for which concrete is a porous and\nabsorbable material, have been studied in order to establish a new non-contact\ninspection technology for maintenance of concrete structures. In this study,\nTHz transmittance and reflectance of concrete in drying process were measured\nwith a 60 GHz GUNN diode and absorption coefficient is analyzed for\nconcrete with various water contents. It is shown that quantitative detection\nbelow 10% is possible for the water content at surface area of concrete....
Cement nanocrystallites constitute the binding phase in concrete, a material\nthat has been around for more than two thousand years and remains the most\nwidely used of manufactured materials. Thanks to their size, their disordered\nnature, their reprecipitation after combination with water, and their rapid\nevolution when the concrete sets, these nanostructures have only been subjected\nto careful investigation quite recently. Nanotechnology is now able to\ncontrol their formation and exploit their evolution (shrinking and swelling)\nduring the setting phase to produce a concrete with a strength and ductility\nclose to those of steels. Furthermore, the analysis of basic nanoscopic reactions\noccurring during setting, and their modification by polymer additives\nacting at the interfaces, numerical modelling techniques are potentially able to\npredict big evolutions and properties of nanocrystallites. Here we discuss the\nfuture of these nanocrystallites in new applications....
To deepen the understanding of the construction safety accidents rules as well as identify and cure the crux of construction safety\nmanagement failures in China, we analyzed the status quo of safety management and identified the ââ?¬Å?last mileââ?¬Â problem, that is, the\nfailure of implementation of the extensive legal and regulatory systems on the construction site. The safety factors were then\nextracted based on a questionnaire consisting of 34 items. Through factor analysis and ranking correlation, five human factors\nwere found to be the greatest challenge and leverage point of safety management at construction sites. Accordingly, a novel safety\nmanagement framework was proposed and tested as part of the Wuhan-Shenzhen highway project. Expert auditing confirmed\nthat the proposed framework could substantially improve the construction safety performance and thus bridge the ââ?¬Å?last mileââ?¬Â of\nsafety management implementation....
Fly ash (FA) has been an important ingredient for engineered cementitious composite (ECC) with excellent tensile strain capacity\nand multiple cracking. Unfortunately, the frost resistance of ECC with high-volume FA has always been a problem. This paper\ndiscusses the influence of silica fume (SF) and ground-granulated blast-furnace slag (GGBS) on the frost resistance of ECC with\nhigh volume of FA. Four ECC mixtures, ECC (50% FA), ECC (70% FA), ECC (30% FA + 40% SL), and ECC (65% FA + 5% SF), are\nevaluated by freezing-thawing cycles up to 200 cycles in tap water and sodium chloride solution. The result shows the relative\ndynamic elastic modulus and mass loss of ECC in sodium chloride solution by freeze-thaw cycles are larger than those in tap water\nby freeze-thaw cycles. Moreover, the relative dynamic elastic modulus and mass loss of ECC by freeze-thaw cycles increase with\nFA content increasing. However, the ECC (30% FA + 40% SL) shows a lower relative dynamic elastic modulus and mass loss, but\nits deflection upon four-point bending test is relatively smaller before and after freeze-thaw cycles. By contrast, the ECC (65% FA\n+ 5% SF) exhibits a significant deflection increase with higher first cracking load, and the toughness increases sharply after freezethaw\ncycles, meaning ECC has good toughness property....
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