Reliability of technological systems of building construction in permanent EPS formwork

Abstract

Technological system (TS) of cast-in-situ reinforced concrete (RC) building construction in permanent EPS formwork is one of the most effective and promising areas of contemporary construction. It is important to determine the level of reliability to improve the efficiency of TS and the quality of construction output. Experience shows that technological defects occur during the construction of RC structures in the permanent EPS formwork. In this regard, reliability assessment of TS on the quality parameters is the relevant. Estimation features of the reliability indices of construction TS is that it can be described mathematically based on the distribution law of observations data. In our study we used the following methods: visual inspection of structures and detection of technological defects; direct measurement of the size of deviations from the design values; statistical analysis of the measurement results; analysis of the qualitative characteristics of constructed structures by the quantitative parameters based on the theory of reliability of TS. It is established that the structural defects in permanent EPS formwork occur during the construction of cast-insitu RC buildings, and those are formed as the panels divergence under the thrust from fresh concrete mix. As a result, the thermal insulation layer of structures reduces, which may lead to the freezing in these parts. Based on the analysis of field measurements and generalizations of statistical data, the values of formation frequency of structural defects are determined, and also the assessment of assignment probability on quality parameters is given.