Current Issue : January - March Volume : 2017 Issue Number : 1 Articles : 5 Articles
In the IBS building maintenance, the conventional methods to the project delivery and its failure to form\neffective communication channel between complementary knowledge on IBS construction and related members that\nis conducted in the sequential manner has resulted in ineffectiveness for managing building maintenance, where a\nparadigm shift within the IBS traditional approach is necessary. The research results described are concerned with i)\nan integrated system to record, diagnose and analyse information for IBS building maintenance to detect patent or\nlatent defect, select an effective repair method, provide appropriate planning decision and reduce risks of defect\nthroughout the building lifetime. ii) building a decision making support in diagnosis in IBS building maintenance\nbased on robust data collection about concrete defects and causes including in the selection of a durable replacement\ndesign and material or the proper rehabilitation method. The system development was based on analysis of number of\ninterviews and case studies conducted with professional engineers working in IBS building maintenance departments.\nThe paper concludes that implementing a CMMS Expert using BIM can help improve the performance of IBS\nbuilding design, construction and maintenance operations....
Therecent rise of terrorist attacks has reinforced the need formitigation of damage caused by blast loading on unreinforced masonry\nwalls. The primary goal of the techniques is to prevent the loss of life while simultaneously preserving the integrity of the structure.\nThis paper presents a compilation of recently available literature on blast protection of unreinforced masonry walls. It seeks to\npresent the state of the art in this field, including mitigation techniques considered as well as testing methods selected. Fiber reinforced\npolymers and polyurea are the two dominant retrofitting techniques being assessed in the field.Other techniques include but\nare not limited to polyurethane, steel sheets, and aluminum foam. Since there is no widely implemented standard for blast loading\ntest procedures, direct comparisons between the efficiencies of themitigation techniques proposed are not always feasible.Although\nfragmentation is an indicator of the efficiency of retrofits, it is currently measured by subjective observation of postblast debris....
This research deals with the durability of micropolymer concrete (MPC) obtained by mixing an epoxy resin with fine and coarse\nsand particles. In particular the resistance of the micropolymer concrete to chemical solutions (citric acid C6H8O7, sulfuric acid\nH2SO4, and hydrochloric acid HCl) is investigated and compared to this of Portland cement microconcrete. Two MPC are tested.\nThe first is formulated with 9% mass fraction of epoxy polymer whereas calcareous fillers have been incorporated in the second\nformulation in order to reduce the percentage of the epoxy binder. It is shown that a microconcrete designed with 7% of epoxy, 10%\nof fillers, and 83% of aggregates is characterized by higher physical and mechanical properties than those of the MPC formulated\nwith 9% of epoxy binder.The mechanical properties of the resultingmaterials after their exposure to the three selected acid solutions\nat different durations were studied through compressive, three points bending and ultrasonic wave propagation tests. The obtained\nresults are compared to those of microcement concretes (MCC) tested under the same conditions as MPC. The results show\nthat both microepoxy polymer concretes exhibit better mechanical properties and highest resistance to chemical attack than the\nmicrocement concrete....
The bridge bearing is one of the component members which provide resting supports between piers and decks. The bridge bearing\nis intended to control longitudinal movement caused by traffic flow and thermal expansion, thereby reducing stress concentration.\nIn high seismicity area, the bridge bearing has been utilized as the base isolation system to mitigate acceleration transferred from\nthe ground. Although the existing bridge bearing installed between superstructure and substructure provides extra flexibility to\nthe base of the entire structure, considerable permanent deformation occurs due to lack of recentering capacity after earthquake. It\nis required to spend extra cost for repairing impaired parts. The bridge bearings integrated with superelastic shape memory alloy\n(SMA) devices used for upgrading the recentering effect into the friction damper are proposed in this study. The refined finite\nelement (FE) analyses are introduced to reproduce the response of such new structures under cyclic loading condition.The bridge\nbearing systems thatmaintain uniformrecentering capability are designed with various friction coefficients so as to examine energy\ndissipation and residual deformation through FE analyses. After observing FE analysis results, optimal design for the recentering\nbridge bearing system will be proposed to take advantage of energy dissipation and self-centering capacity....
Cement fly-ash gravel (CFG) pile is a widely used ground reinforcement technique. This paper aims to address the mechanical\ncharacteristics of CFG composite foundation in consolidating saturated mine tailings (MTs) dam. The field static load tests were\nemployed to explore the bearing capacity of the CFG composite foundation, and finite element (FE) models in three dimensions\nvalidated through comparison with experimental results were used to discuss the pile-soil stress distribution and pile-soil stress\nratio of the CFG composite foundation. The results indicate that the distribution of earth pressure and pile stress is relatively\nhomogeneous and stable over depth and load, while the development of CFG composite foundation bearing capacity is insufficient,\nin which the developed bearing capacity of CFG piles is less than 50% of its characteristic value. Additionally, compared with the\nlaboratory model test results, the pile-soil stress ratio decreases with the increasing of the load in FEM results proved to better\nconform to the actual engineering conditions. Furthermore, the deformation modulus and thickness of cushion exert significant\ninfluence on pile-soil stress ratio and integral bearing capacity of CFG composite foundation....
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