Energy-Efficient Accelerated Curing of Concrete for Plant-Produced Prestressed Concrete

Abstract

T he cost of energy is at an all-time high and continues to rise. Therefore, any industry which employes an energy-intensive process needs to develop information to optimize that process. The prestressed concrete industry is no exception, with its necessity to attain high early-age compressive strengths of approximately 3500 to 5500 psi (24 to 38 MPa), usually at an age of 14 hours or less. The technical literature does not contain information to guide a producer of precast prestressed concrete products to optimization of curing at elevated temperatures. Studies l 2 in the 1960's concentrated on developing the highest early-age compressive strength possible in a given length of time, with little regard to the expenditure of energy which then was inexpensive and in seemingly endless supply. This laboratory study was designed primarily to provide the producer of precast prestressed concrete products with curing techniques which are capable of developing high early-age compressive strengths while significantly reducing the levels of heat energy consumption. Prior to undertaking this laboratory study, an extensive state-of-the-art re-