CONCRETE PLACING ANALYSIS USING DISCRETE-EVENT SIMULATION

The concrete delivery and pumping process is a stochastic system. if a nalysed deterministically there is the danger that the negative effect s of the random distribution of events are not taken into account, lea ding to poor estimates of production and cost. By representing the sys tem as a random process the construction engineer can, first, achieve improved estimates of the overall productivity and thus schedule deliv eries better, and, secondly, determine the effect of unanticipated eve nts such as excessive delivery or pour times. This paper presents a st ochastic model of the delivery and pumping of concrete. By investigati ng data gathered from a major civil engineering project, the random na ture of the process has been represented within the model by means of the gamma probability distribution. The model has been analysed using discrete-event simulation techniques, which have been used successfull y in other civil and production engineering applications. Experimental analysis of the model has indicated that it can provide estimates of the performance of concreting operations that are more realistic than those obtained if the system is analysed on a non-random basis. The ma in conclusion is that for every concreting operation there is an optim al combination of truck interarrival and concrete pump times that will maximize the utilization of the plant and minimize the duration of th e operation. This optimal cannot be calculated deterministically and i s different from that derived from the non-random model.