Key Research Issues Of Glazed Hollow Bead Insulation Concrete Applied To Real Buildings

With the continuous increase of building energy consumption in ourcountry, new buildings will require higher energy efficiency standards. Manybuilding fire accidents happened in recent years were due to safety risk of theinsulation system installed on the external wall. To overcome the drawbacks ofexisting energy-saving technologies, it is imperative to develop a buildingenergy conservation technology integrated with the functions of bearing andthermal insulation.Building19located in the sub-district of Phoenix developed byJincheng-Mingji was the first demonstration project using glazed hollow beadthermal insulation concrete (GHBTIC) in China, in which the GHBTICdeveloped in the laboratory was applied for the first time to an actual largesingle building. This research addresses the following critical technical issueswhich need to be resolved during the construct process this particulardemonstration project: (1) Research on the key technologies of pumping (GHBTIC). Thisstudy addresses two problems concerning pumping of GHBTIC: GHB floatingin mixing and the mortar segregation and delamination of broken GHB due topumping process. The work performance of pumping GHBTIC was studied.The influences of different affecting factors on the uniformity and workabilityof pumping GHBTIC were investigated and the method for controlling theuniformity and workability was proposed. In addition, the mix design ofGHBTIC was optimized and a method of calculating the water usage forpumping GHBTIC was proposed for satisfying the design strength requirementof the demonstration project, Building19. The optimized mix proportion ofGHBTIC was proposed to pump GHBTIC.(2) Research on the earthquake resistant performance of shear wallmembers in Building19. In this research, the scale of shear wall member toreinforcement design is1:1.5. Based on the research of earthquake resistantperformance indexes, including breakage form, bearing capacity, hysteresiscurve, and skeleton curve of shear wall, the influence rules of differentaffecting factors (shear span ratio, axial compression ratio) on earthquakeresistant performance of shear walls made of GHBTIC were stiudied. Also,compared with that made of the conventional concrete, the earthquake resistantmechanism of shear wall structure made of GHBTIC was revealed. Based onthe experiments research, by using finite element software ABAQUS, it’scarried out that numerical simulation of shear wall made of glazed hollow bead thermal insulation concrete, and its results is compared and analyzed withactual test results.(3）Dynamic earthquake resistant analysis of Building19. On the basisof theoretical design, the seismic performance of this project was studied usingthe finite element software, SAP2000. The two common analyses wereperformed: response spectrum analysis and time-history analysis. Thevibration frequencies of Building19were determined by the modal analysis.The bottom shears and the layer displacement angles were calculated underthe horizontal earthquake loading (X-direction and Y-direction) through theresponse spectrum analysis method. The deformation and force responses werestudied considering three seismic waves (EL Centro wave, Tangshan wave,and one artificial wave) by using the time-history analysis method. At thesame time, a model for common concrete shear wall buildings was establishedto compare with Building19project to demonstrate the seismic performanceof Building19.(4）Detection and analysis of the key performance indicators forBuilding19demonstration project. This project was monitored and its bearingstrength and thermal insulation performance were detected and analyzed.Through the differential results observed between the real structure and thelaboratory one, the effect of the moisture ratio on the thermal conductivity ofGHBTIC shear wall was evaluated and the whole project was analyzed fromthe view of economy. The results show that the comprehensive cost of the GHBTIC is lower than the ordinary concrete and thus presents a strongermarket competitiveness with high return value.After tested by the associated authorities, the bearing strength andthermal conductivity of GHBTIC have been shown to satisfy the designrequirements. This project demonstrates a clear evidence to the GHBTICpatent, ZL2006l0012726.2and received the first three-star green buildingdesign certification in Shanxi Province. Further, the first national industrystandard “The application technical regulations of GHBTIC” was developedbased on the concluding results, which is currently under a final review.GHBTIC structure has both thermal insulation and load-bearing performancesmeeting the design needs with no additional cost to form a new heat insulationhexahedral structure. This new energy-saving structure distinguishes from theconventional single insulation structure pattern as the outer wall heatpreservation system. Earlier relevant researches combined with the successfulexperience from the demonstration project pave a solid foundation consideringthe adoption the GHBTIC nationwide.