Current Issue : October - December Volume : 2020 Issue Number : 4 Articles : 5 Articles
Estimation of basic material consumption in civil engineering is very important in the initial phases of project implementation. Its\nimportance is reflected in the impact of material quantities on forming the prices of individual positions, hence on forming the\ntotal cost of construction. The construction companies use the estimate of material quantity, among other things, as a base to make\na bid on the market. The precision of the offer, taking into account the overall conditions of the business realization, directly\ninfluences the profit that the company can make on a specific project. In the early stages of project implementation, there are not\nenough available data, especially when it comes to the data needed to estimate material consumption, and therefore, the accuracy\nof material consumption estimation in the early stages of project realization is smaller. The paper presents the research on the use\nof artificial intelligence for the estimation of concrete and reinforcement consumption and the selection of optimal models for\nestimation. The estimation model was developed by using artificial neural networks. The best artificial neural network model\nshowed high accuracy in material consumption estimation expressed as the mean absolute percentage error, 8.56% for concrete\nconsumption estimate and 17.31% for reinforcement consumption estimate....
Automatic monitoring system is one of the main means to ensure the safety of underground engineering construction. This paper\nsummarizes the current international research and application status of the underground engineering monitoring system from\nthree aspects of data acquisition, data transmission, and data processing and emphatically introduces the mainstream new\ntechnology of the monitoring system. Furthermore, this paper puts forward specific and implementable technical routes based on\nthe current intelligent technology and the challenges faced by future monitoring, which can provide direction and reference for\nfuture research, including high-precision real-time acquisition and safe and reliable transmission of monitoring data, multisource\ndata fusion, and the visual intelligent early warning platform....
Accurate project progress measurement is critical for effective project management.\nBesides guarantying smooth work progress, it affords project managers\nthe chance to identify early warning signs for peremptory remedial actions\nto keep the project on schedule and to budget. However, pertinent barriers\ncan suppress the realization of the benefits of an accurate assessment of\nconstruction progress. This study aims to identify, examine and prioritize the\ncritical barriers militating against accurate project progress measurement in\nthe Ghanaian construction industry. Sixteen barriers identified from the literature\nwere administered in a questionnaire survey to professionals with tier\none construction firms and consultants. Sixty experienced construction professionals\npractising with tier-one construction firms and consultancy services\ntook part in the survey. The relative importance index technique was used\nto rank the factors and correlation in responses of the two parties tested by\nthe Mann-Whitney U statistics. The most critical barriers perceived by the\nprofessionals were 1) Reliance on Supervisorâ??s Judgement, 2) Generic and\nNon-Systematic Approach, 3) Variable Quality of Data and 4) Intricate Measurement\nReports. Other highly ranked barriers include 5) Lack of Timely\nInformation, 6) Laborious Data Gathering and 7) Quality Integration Constraint.\nThe findings underpin the need to minimize dependence on subjective\nopinions and mere experiences of supervisors for assessment of project\nprogress in this age of information technology. Incorporation of a level of\nautomation into traditional progress methods will not only reduce human\nerrors introduced into manually collected data but facilitate visualization of\nprogress reports. Contiguous to a clear specification of the method of progress\nmeasurement in the contract document, a system that conveniently integrates\ncost, time and scope of work into progress measurement must be pursued.\nAddressing these identified critical barriers will consolidate current construction\nprogress management practices....
Because of its advantages of light weight, high strength and convenient construction,\nsteel structure has gradually become the first choice for large-span\nand high-rise structures. The use of high strength steel in building engineering\ncan reduce the section size of components and the weight of the structure,\nthus increasing the building area. But steel is not fire-resistant, when the\ntemperature reaches 600 Degree C, steel loses most of the stiffness and strength.\nTherefore, it is of great significance to study the fire resistance of steel structures,\nand the mechanical properties of steel structures at high temperature\nare the foundation of the fire resistance research. The mechanical properties\nof steel after high temperature are the basis for the safety assessment of steel\nstructure after fire. Therefore, this paper studies the mechanical properties of\nQ345 steel after high temperature cooling....
Using recycled aggregate from construction and demolition (C&D) wastes as a construction material is a potential method for\nsolving the disposal of C&D wastes, which can reduce the exploitation of natural aggregate. In this study, extensive laboratory tests\nwere carried out to investigate the reliability of the C&D wastes used as road base material. Meanwhile, the gradation design and\nthe dominant aggregate size range were considered, and a physical disposal method was proposed to enhance the structural\nperformance of the recycled material by replacing the skeleton of the recycled aggregate (RA) with high-quality limestone. The test\nresults showed that (1) given the high absorbency and fragility of C&D wastes, its RA was not enough to provide the strength and\nstability required by the base; (2) the compaction characteristics of the RA are quite different from that of the limestone aggregate,\nbut the final compaction effect is basically the same; (3) the replacement treatment proposed in this study is an effective approach\nto improve the performance of the recycled granular base because the breakage rate decreased by at least 28.2%and the mechanical\nproperties increased by approximately 50% compared with that of the untreated specimen; and (4) when the limestone content\nreached 75%, the California bearing ratio and the resilient modulus of the graded B specimen exceeded 120% and 200MPa,\nrespectively, satisfying the pavement requirement in medium traffic.m...
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