In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Become an ACI Member
Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
American Concrete Institute
38800 Country Club Dr.
Farmington Hills, MI
Feedback via Email
Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Title: Rapid Microwave Curing of Precast Concrete Slab Elements
Author(s): S. L. Mak, D. Ritchie, G. Shapiro, and R. Banks
Publication: Special Publication
Appears on pages(s): 537-552
Keywords: concrete; curing; microwave; precast; speed; strength;
Abstract:The speed of curing is often a critical issue in the manufacture of precast concrete elements. For some products, the curing cycle consumes up to 70% of the total production cycle. To improve the speed of production, heat curing is often used to accelerate the hardening of precast concrete. Conventional heating techniques rely on thermal conduction. Microwave energy offers a potential to increase the rate of bulk heating in precast concrete through its relatively deeper penetration, which allows quicker through-depth heating and maturing. Research on microwave curing of concrete has been ad hoc in the past and a wide range of issues remain unresolved. These encompass materials-microwave interactions, process design and control, hardware and logistics, as well as the impact of microwave curing on concrete properties. In this paper, progress on research on microwave curing is described with reference to work carried out at CSIRO. In particular, results from pilot-scale heating of slab-type elements are discussed in relation to heating characteristics, process control, set acceleration, strength development and process efficiency. Our results show that for the same bulk heating rates, microwave heating produces significantly lower temperature gradients when compared to steam heating. Using rapid curing cycles of less than six hours, compressive strengths in excess of 25 MPa can be achieved in high quality precast concrete. Doubling the bulk heating rate using microwaves does not result in any deterioration in near-surface quality as was the case with conventional steam heating.
Click here to become an online Journal subscriber