Mechanical Properties of Sprayable Fiber Reinforced Strain-Hardening Cement Composite (SHCC) for Seismic Retrofitting of Existing Infrastructures

기존 시설물의 내진보강용 뿜칠형 SHCC의 역학적 특성

Sprayable fiber reinforced strain-hardening cement composites(SHCCs) were developed for seismic retrofitting of existing infrastructures, especially, for packing the joint between existing R/C building and seismic retrofit elements. In this paper, influence of mixture proportions on the mechanical properties, such as compressive, flexural and direct tensile performances, of sprayable SHCCs is investigated. Sprayable SHCCs developed in this study were reinforced with synthetic PVA fibers at the volume fraction of 2.2%. Mechanical properties of SHCCs were evaluated on the specimens manufactured after mixing, pumping, and shotcreting. The test results indicate that the compressive strength and elastic modulus of three SHCC mixtures increased almost linearly according to shotcreting procedure from mixer to nozzle. And the direct tensile and flexural behavior of SHCC mixture(SHCC-C) with AE agent was superior to the those of the other SHCC mixtures(SHCC-A and-B). It also has very high pumpability and sprayability characteristics.