Current Issue : October - December Volume : 2016 Issue Number : 4 Articles : 5 Articles
With the increasing population and the consequent needs for transport facilities, the construction\nof tunnels in urban environments is fast growing. Tunneling at each depth of the soil, causes\nchanges in the earth�s surface; this is more important about urban areas tunnels, especially when\ncrossing the residential areas, so having knowledge of their performance is really important. Some\nof the consequences of underground tunneling are earth surface moving around the tunnel,\nmovement of tunnel�s surrounding and changes in earthquake acceleration. The performance and\nbehavior of underground structures have been studied by numerous researchers, but the effect of\ntunneling on earthquake records and its effects on aboveground structures have been getting less\nattention. The current article will try to study and examine the changes in seismic velocity at\nground level, structural response spectrum, and Fourier spectrum with digging a circular tunnel.\nThe results show that digging a circular tunnel at ground level will cause a change in the earthquake\nrecords profile....
There is a global trend for seismic response improvement of new buildings to reduce cost and\nfuture damage. It is also important to improve existing structures that are designed without\nconsideration of seismic load or using old provisions that cannot meet the new one. The objective\nof this paper is to draw attention to evaluate existing reinforced concrete school buildings,\nthen to present a proposed methodology to improve the behaviour of such schools with low cost\nespecially in a developing country. The proposed method uses overhead water tanks as a tuned\nmass damper. A pushover analysis has been performed to evaluate the existing schools and\nperform a feasibility study to select the best solution to achieve seismic response improvement\nof the existing structure. Of course, the proposed methodology can be applied easily to other existing\nstructures....
The use of earth construction is well established in energy efficient housing. Mud bricks consist of\nclay, water, and binding material such as rice husks or straw. The advantages of mud brick include\nits low-cost and great thermal behavior. Although mud brick is considered one of the oldest construction\nmaterials, engineers and builders do not have enough information about its mechanical\nproperties. Also there is no accurate design code to follow before construction. This study is devoted\nto enhance the low compressive strength of mud brick without sacrificing its low thermal\nconductivity properties. The experimental program in this research includes the use of different\nadmixtures to increase the compressive strength of the basic mud mix. The experimental results\nshow that the increase of cement ratio, as ingredient to a certain limits, can lead to an optimum\ncompressive strength of the brick....
The compressive stress-strain behavior and other characteristics of treated fly ash based roof tiles\nhave been studied by several experimental tests. This paper attempts to presents the results and\nobservations of a study and comparison based on the past reported experimental data. Based on\nthe results and observations of the comprehensive experimental study, five ââ?¬Å?control pointsââ?¬Â have\nbeen identified. The new sets of experiment have been carried out to investigate whether it might\nbe possible the use of fly ash in fly ash based roof tiles for residential construction. In the present\nstudy, treated fly ash (TFA) of C category was used with different materials as a replacement of\nclay for making treated fly ash stone dust roof tiles (TFASDRT). Treated fly ash stone dust roof\ntiles (TFASDRT) were studied at varying percentages of cement, coarse sand, and radish stone\ndust (RSD) along with the constant percentage of waste polythene fibre (WPF). A research program\nwas undertaken to evaluate the suitability of such test for assessing the properties of treated\nfly ash stone dust roof tiles (TFASDRT). The result of this study recommends that the fly ash based\nroof tiles provides a sustainable supplement to the traditional clay roof tiles, they increase the efficiency\nof traditional roof tiles and significantly help to reduce the environmental issues associated\nwith the disposal of these waste materials....
Within the past two decades or so, the asphalt paving industry has responded positively to increasing\nglobal concerns over shrinking natural resource reserves and worsening environmental\nconditions through the development and deployment of warm-mix asphalt technologies. Such\ntechnologies make it possible to produce and place asphalt concrete at reduced temperatures\ncompared to conventional hot-mix methods. Several studies have reported on the potential of\nwarm-mix asphalt with regard to improved pavement performance, efficiency and environmental\nstewardship. This paper reviews several of those studies in the context of pavement sustainability.\nOverall, warm-mix asphalt provides substantial sustainability benefits similar to or, in some cases,\nbetter than conventional hot-mix asphalt. Sustainability benefits include lower energy use, reduced\nemissions, and potential for increased reclaimed asphalt pavement usage. Growth in utilization\nof warm-mix asphalt worldwide may, in the not-too-distant future, make the material the\nstandard for asphalt paving. Regardless, there are concerns over some aspects of warm-mix asphalt\nsuch as lower resistance to fatigue cracking, rutting and potential water-susceptibility problems,\nparticularly with mixes prepared with water-based technologies, which require further research\nto address....
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