An experimental study into the evolution of loads on shores and slabs during construction of multistory buildings using partial striking

This paper describes a full-scale test on a building constructed so as to enable study of the transmission of loads between slabs and shores during the processes of shoring and striking. The experimental model consisted of a 3-storey building with slabs made up of reinforced concrete. The structure was built using a procedure which includes an intermediate stage during striking, known as clearing. This involves removing the formwork boards and a certain number of shores before the pouring of concrete of the uppermost slab. This operation helps optimise the construction process since most of the formwork and shoring material is recovered in only a few days. The loads on the shores were measured by placing 3 strain gauges on each one of them. The results obtained differ notably from those estimated by the simplified methods commonly used. They show that, due to the clearing operation, the shores experience an average unloading of up to 49%, transferring this load to the slab that has been subject to clearing. In the stages that follow the hardening of the concrete, the spread of the loads among the shores is not uniform as the shores furthest away from the columns suffer more loading than the rest. (C) 2009 Elsevier Ltd. All rights reserved.