CONSTRUCTION LIVE LOADS ON SLAB FORMWORKS BEFORE CONCRETE PLACEMENT

A description is given of a survey of live loads on slab formworks in multistory concrete buildings during construction. The survey was cond ucted during the period 1987 to 1990 and embraced over 22 concrete bui lding projects in several different cities. In this survey, data were collected on the materials and equipment stored on slab formworks and the worker's load. The live loads supported by slab formworks change c ontinuously during construction. This paper studies the live loads on formworks before the concrete slab is poured. The survey procedure and a statistical analysis of the collected data are presented. The stati stical moments of equivalent uniformly distributed loads for formwork member load effects are obtained by using the covariance function deve loped for the observed live loads and formwork member load effect infl uence surfaces. A distribution function for formwork member load effec ts is investigated and fractiles of the calculated equivalent uniforml y distributed loads are compared with the current formwork minimum des ign load recommendations.