Engineering properties of two-stage concrete: A critical review

Abstract

Conventional Concrete (CC) is a highly used material in construction industries. CC has certain advantages and disadvantages depending on materials, material proportions, and method of preparation. Flaws like lesser sustainability and higher cost of production create the necessity of research to find an alternative solution. Two-Stage Concrete (TSC), also known as Preplaced Aggregate Concrete (PAC), which is similar to the CC on the basis of its constituent materials. However, it is produced using a unique procedure that differs from conventional concrete. Production of Two-Stage concrete is done in two stages. Initially, coarse aggregates are filled in a tight formwork or mold and then voids between the aggregates are filled by injecting cementitious grout. This unique placement technique changes the load-transfer mechanism in TSC, leading to improved mechanical properties.This paper critically reviews the TSC, including its history of development, engineering properties, long term performance, and construction methods that enhance the understanding of its behavior, thus paving the way for wider implementation of TSC in today’s construction industry. From the study, several conclusions are drawn and it is seen that TSC is used in the construction of Nuclear Power-Plants and Bio-chemical storage plants to minimize segregation problems. TSC makes construction cost-effective due to the higher percentage of coarser particles and improves mechanical properties with partial replacement of constituents without affecting its strength.