Analysis of casting rate for the validation of models developed to predict the maximum lateral pressure exerted by self-compacting concrete on vertical formwork

Abstract

The design of vertical formwork is governed by the lateral pressure exerted by fresh concrete; while maximum lateral pressure is the key parameter for formwork design, the rate of pressure decay and the time needed for pressure stabilization are important for determining formwork removal time.An analysis of different models for predicting the lateral pressure generated by SCC on vertical formwork was carried out, raising the issue of a fundamental parameter like the casting rate. The work also compiles experimental data published over 15 years. A total of 137 experimental data points were collected, 131 for SCC poured from the surface of the formwork and the remaining 6 for SCC pumped from the bottom of the formwork.Experimental data obtained from different authors were utilized in order to compare the adequacy of the different models in three zones: experimental data with casting rates under 3m/h, experimental data with casting rates between 3 and 10m/h, and experimental data with casting rates over 10m/h. The results were established by not only taking into account the three different zones, but also the formwork safety .