ECC로 보강한 비보강 조적 벽체의 횡력 저항 성능 향상

Abstract

Performing remodeling or change the usage of building, URM walls which used commonly in apartment as non-structural element need to have reliable performance of buildings because removal of this types of wall could make more wastes in construction site and removal procedure may cause delay of construction. One technique to enhance lateral resistance of these structures is to retrofit the URM walls using shotcrete. However, using normal shotcrete, cannot improve ductility and may cause brittle failure at wall-frame or slab connection. However, recent study for new materials, such as ECC or UHPC, can solve these problems increasing ductility and toughness of retrofitting materials. In this study, we use sprayed ECCs for retrofitting of URM wall. ECCs can be designed to work in conjunction with existing walls to increase both strength and ductility for in-plane behavior of the URM walls by spray. And this may change non-structural masonry wall to structural wall increasing stiffness of wall. To ensure that this technique will perform its intended purpose, in-plane lateral loading test was performed. The results of lateral quasi-static testing of two retrofitted URM compared to non-retrofitted one. Two retrofitted walls are consisted of just sprayed and anchored to wall base, RTM-ECC and have wiremesh, same detail of others, RTM-ECC-WM. Retrofitted specimens show significant increase of strength, ductility and energy dissipation capacity compared to URM. RTM-ECC show stiff strength degradation however, RTM-ECC-WM show slow degradation of strength because of the load transferring effect of wiremesh.