Model za prognoziranje produktivnosti procesa betoniranja

Measuring of the productivity of work in civil engineering, as a very complex and long lasting process because of the peculiarities of construction activity is not sufficient per se; it is necessary to examine and assess the impact of various factors on the realized productivity. Concreting works, in construction of an engineering structure, have a great importance from the viewpoint of quantities and costs, especially if frame construction system has been implemented in building construction. For such buildings, concrete works represent key activities in the dynamic plan of construction works. For this reason it is important to perform realistic planning of construction works by good coordination of all factors and by providing the required productivity. In our practice, planning of concreting process, mostly boils down to experience without considering the factors which affect the productivity of the process. The subject matter of scientific research of this doctoral dissertation is the analysis of productivity of performing concreting works when constructing engineering structures and development of regression and simulation models for concreting process productivity prediction. Concrete works technology which is the subject of dissertation analysis comprises making of concrete in concrete factory, transport using mixer trucks to the construction site, transport with concrete pump to the placing location and placing using poker vibrators. In the dissertation the process of concrete works performance was researched as a cyclic process in civil engineering, on actual and ongoing projects for the purpose of obtaining actual data. The data were acquired by recording the concreting process, by studying technical and design documents and from interviews with technical and working personnel directly engaged in the process, on eight building construction sites and they were used for development of regression and simulation models for predicting the concreting process productivity. The analysis of the productive of concreting process of vertical (columns, walls, bearing walls, elevator shafts) and horizontal elements of engineering structures (beams, slabs, floor structures, foundation slabs) has been conducted. By implementing empirical, statistic, regression and simulation methods, the models for concreting process productivity prediction were formed. The proposed models can be useful in the planning phase and provide for a more accurate predict of activity duration in the concreting process and thus be beneficial for the decisions making, predicting of the course of works and for a better management of concreting process with a goal of increasing productivity, shortening works duration and reduction of cost