Advanced Materials Research Vols. 446-449

Abstract: Wall-slab structural system is a system suitable for use in the field of high-rise building where the main load resisting system is in the form rigidly connected wall slab member. Concrete vertical walls may serve both architecturally partitions and structurally to carry gravity and lateral loading. Moment transfer of joint is an important aspect for proper structurally functioning of wall-slab system. Hence, the main aim of this study is to investigate experimentally the effect of reinforcement details in the wall on bending capacity for support stiffness in wall-slab system for residential project in Malaysia. A total of six wall specimens were tested based on the specification given by the project contractor. Three of this specimens consisted single layer of rebar while another three specimen consisted of double layer of rebar. The size of the wall-slab’s specimens is 1000mm in length (L), 1080mm in width (W), 1000mm in height (H) and 80mm in thickness (T). The average concrete strength was 23.49MPa with Grade 30N/mm2 and the average yield strength of R5 bar was 817MPa. The predicted bending capacity at failure is in the range from 5.36kNm to 7.12kNm, depending on actual concrete cover. The bending capacity at failure for single layered of rebar in wall for specimen 1, 2 and 3 were found to be 3.59kNm, 3.81kNm and 3.15kNm, respectively. The bending capacity at failure for double layered of rebar in wall for specimen 1, 2 and 3 were 5.50kNm, 6.31kNm and 7.00kNm, respectively. The average percentage difference in stiffness of double layered of rebar in wall based on load-deflection curve obtained is in the range from 116.17% to 289.88% higher than single layered of rebar in wall. Based on the experimental results, specimens consisted of double layered of rebar in wall is found to provide higher bending capacity to the joint of wall-slab structural system in the range from 56.25% to 98.86% compared with single layered of rebar in wall.

Abstract: Construction technology of fair-faced concrete was successfully used in China Qingdao Zhuoting plaza project. Its No.1 and No.2 dwelling houses are high-rise buildings and their posts and external walls were constructed with fair-faced concrete. As it is the highest fair-faced concrete project in China with 99.95m in height , four different concrete strength grades from C35 to C50 on different floors,370 days construction period through different four seasons in a year, the project meets a lot of problems and challenges. In this article, some innovations and key construction technologies were studied and used which make the project be successfully completed.

Abstract: Four formwork support units were experimental studied by heaping load,including three glass fiber mat reinforced thermo plastics (GMT) formwork support units and one 18mm plywood formwork support unit. Compared with 18mm plywood formwork support unit, the vertical poles force distribution in GMT formwork support units were analyzed. The experimental parameter also included vertical poles height difference and their values were follows: 0mm, 2mm and 4mm. The results showed that the vertical poles force distribution are uneven in GMT formwork support unit and vertical pole height differences have influence on their force distribution.

Abstract: Zhishin clay and Black Hill bentonite are used as raw clay materials in this study. These clays are mixed with Taitung area hard shale to produce the backfill material for potential application as barrier for the disposal of low-level radioactive waste. The interaction between concrete barrier and the backfill materials is simulated by an accelerated migration test to investigate the effect of concrete on the expected functions of backfill material. The results show some decrease in swelling potential in the backfill material near the interface. Also, backfill material close to the contact with concrete exhibits greater change in the ratio of calcium/sodium concentration, due to the release of calcium ions from the concrete material.

Abstract: As a new kind of concrete construction technology, fair-faced concrete is still not mature and applied widely in China by present. But it was successfully used in China Qingdao Zhuoting plaza project. Its No.1 and No.2 dwelling houses are high-rise buildings with thirty-two stories and their external walls were constructed with fair-faced concrete. As it is the highest fair-faced concrete project in China with 99.95m in height and 370 days construction period through four seasons in a year, the project meets a lot of problems and challenges. So some innovative construction technologies were studied and used which make the project smoothly and successfully completed and get many significant economic, social and environmental benefits.

Abstract: From the characteristics of rock damage, the mechanism of rock blasting into seam was discussed. Based on the joint mechanism of stress waves and explosive gases, the blasting method adopting slotted pipe charge structure in fault formation was studied, and the test results were used in Guanjiao tunnel of Qinghai-Tibet railway. The field tests show that the perimeter hole adopting slotted pipe charge structure improves the phenomenon of over-excavation in fault formation obviously.

Abstract: Each layer of super high tower body is outwards protuberant, scaffoldding cantilevered end larger. This paper analyzes and researches the ultra-high tower overhanging scaffolding construction preparation, high scaffold material requirements, construction requirements, scaffold erection and dismantling construction technology and other aspects, it solves the high difficulty in construction, and provides practical basis and construction experience for super high steel tower mast structure.

Abstract: At present, the installation of flue gas heat exchanger have not uniform method of working at home and abroad. The Install process using different items, By analyzing the duration and cost of using different construction techniques of several 2 × 200MW-scale projects,I found that the range of 31% difference in duration, the cost difference between the range of 23% (having regard to price factors),it is necessary to develop efficient installation process to reduce costs and improve efficiency. The study of this process more than 2 × 200MW unit boiler desulfurization system installation to determine the formation of national construction method and lay a solid foundation.

Abstract: The shaft drilling method is a fully mechanized operated mine shaft sinking method when shaft sinking through the soft and weak overburden layer. the new full section boring method can reduce the number of reaming, the number of bits, energy consumption and increase completed advance rate of shaft over 20%, reduce emissions of waste drilling mud by 20% . The paper in detail stated the features of the Full Section boring method operation，the implementation mode，design principle and support technology．

Abstract: In this paper, with the help of program Thufiber, fiber model is used to simulate bridge piers, solid element is used to simulate the superstructure in program MSC.Marc. The effects of the travelling wave on the nonlinear seismic response of the long-span continuous rigid-frame bridge with high piers are analyzed under 2008 Wenchuan Earthquake Wave excitation. The results show that travelling wave has much effect on displacement and shear force of high piers of the bridge. The displacement of the pier top decreases 20% to 50% and the shear force at the pier base increases from 20% to 30%.