Recycled Concrete Aggregate (RCA) Thai reverse logistics supply chain management for ready mix plants

Abstract

Thailand and namely Bangkok is currently experiencing a construction boom. New condominiums are being erected throughout the city and the construction material of choice is concrete. Concrete is being produced by mixing water, cement and aggregates. The concrete plant can be either on-site or off-site, in this case the concrete needs to be trucked from the ready mixed plant to the job site. The raw materials (cement and aggregates) for the concrete have to be shipped to the concrete plant. Aggregates are either fine or coarse and are made by crushing rocks or hardened concrete which results in so called recycled concrete aggregates (RCA). The composition of concrete waste (RCA) is Ca (21.9%), Si (8.27%), Al (4.58%), O (53.51%), C (11.74%) [1] and RCA has similar strength and properties as rock from the mountain. In this case the RCA can be either generated on-site by demolition the existing structure or from a designated quarry site or other demolition site. The objective of the study was to look at all three cases and the advantages and challenges associated with the RCA production site from a logistics management perspective.  The main savings found are in terms of transportation costs (fuel and time) when comparing RCA to aggregates from a remote natural quarry. There are additional intangible savings in terms of global warming in the production process and the energy used in mining the raw material as well as disposal costs for the existing structure. The study used an on-line web enabled survey of young logistics management professionals to compare their perceptions of the various scenarios in a Thai context and analyzed the findings statistically using SPSS in order to create a theoretical model for RCA as part of a sustainable ready mixed concrete supply chain in Thailand and ASEAN.