Development of new layered compression casting approach for concrete

Abstract

Compression casting is a highly effective approach for improving the performance of normal concrete significantly without any additional material/chemical and extra costs. The technology is suitable for manufacturing precast concrete members. However, compression casting of full-scale structural members like beams and columns is challenging due to the high compression pressure required and the limitations of the load-bearing capacity of mould and casting facilities. This study proposes a Layered Compression Casting (LCC) method to overcome the aforementioned problems. For this reason, the influence of casting parameters, including compression pressure P, height of casting layer H, compression duration T, cement content C, water to cement ratio W/C, and Recycled Aggregates (RA) dosage, on the compressive strength, peak strain, elastic modulus, and stress-strain behavior of LCC concrete is investigated. The results reveal that the compressive strength and modulus of elasticity of LCC concrete are significantly improved compared to traditional concrete (up to almost 100% and 50%, respectively). Based on the results obtained from this study and considering compression casting efficiency, the following optimum LCC parameters are recommended: H = 300 mm, P = 15 MPa, and T = 2 min. Furthermore, empirical models are developed/evaluated to predict the compressive strength, peak compressive strain, elastic modulus, and stress-strain relationship of the LCC concrete.