212 / 2022-06-07 16:43:50

Development and structural implementation of LC3 concrete using raw materials in South China

Limestone calcined clay cement (LC3),Hydration,Bond-slip,Shear resistance,Reinforced concrete

Limestone calcined clay cement (LC3), consisting of ordinary Portland cement (OPC) clinker, calcined clay, limestone powder, and gypsum, has been considered a promising solution to current challenges in the cement and concrete industry, such as high carbon emissions, high energy consumption, and resource shortages. The first part of this study presents a series of experimental investigations of LC3-based paste, mortar, and concrete, including microstructural analyses and macro-scale testing, using raw materials from south China. The results show that, in LC3 paste, the replacement of clinker by calcined clay and limestone leads to an increased volume of small pores but decreased total volume of pores. The workability of LC3 mortar and concrete can be readily tailored using conventional superplasticizers. When designed for comparable 28-d compressive strength, the LC3 concrete tend to have lower early-age compressive strength, but comparable compressive strength and higher flexural strength than those of the OPC counterparts at late ages.



To further evaluate the reliability and short-term structural performance of reinforced LC3 concrete members, the second part of the present study focuses on flexural and shear behavior of reinforced concrete (RC) beams using the new developed ecologically green cement consist of limestone, calcined clay and cement clinker (LC3). Full-scale flexural and shear tests were conducted on RC beams with varying reinforcement ratio, concrete strength, shear-span-to-depth ratios and stirrup reinforcement ratios. The test results showed that the crack development and failure modes of LC3 concrete beams were similar to those of OPC beams, both of which exhibited typical flexural and shear failure. The flexural and shear resistance of LC3 concrete beams was evaluated by Chinese, American and Eurocode codes, and the Chinese code had the closest predictions. These findings on LC3 concrete provide fundamental information and guidance for furthering the application of LC3 binder in structural concrete in the near future.