Volume 11 Issue 4 ( December 2024)

One of the key technologies for achieving sustainable concrete construction is the development of carbon- neutral or green concrete. The goal of creating zero-carbon concrete is a long-term endeavor. Currently, numerous efforts are underway to produce Portland cement materials with a reduced carbon footprint in their production. This paper discusses the development of high-performing concrete, specifically high early-strength concrete, utilizing environmentally friendly hydraulic cement (based on Indonesian Standard, SNI 8912: 2020) manufactured by PT. Semen Indonesia (Persero) Tbk. The concrete mixture is designed according to the key performance indicators established for high early-strength concrete, which include a flexural strength of 4.50 MPa at three days of age, an initial slump of 20.0 ± 2.0 cm, and an initial setting time of 8.0 hours. The hydraulic cement used is labeled HCN and HCT. Normal Ordinary Portland Cement (OPC) serves as a baseline for standard OPC concrete. Two types of concrete admixtures are employed to optimize the dosage in the concrete mixture to control the development of high strength and workability parameters, ensuring that the key performance indicators are met. Trials of concrete mixtures with a low water-to-cement ratio are conducted, with a maximum cement content of 500 kg per m3 of concrete mixtures. The results indicate that, in general, trial concrete mixtures based on hydraulic cement can meet the key performance indicators established for the formulation of high early-strength concrete. Specifically, it has been found that the hydraulic cement-based concrete mixture labeled HCN, with cement-to-water ratios of 0.28 and 0.30, performs the best, achieving the targeted key performance indicator while reducing CO2 emissions by up to 13.64% compared to the OPC-based concrete.

Keywords: Hydraulic Cement; Admixtures; High Early Strength Concrete; Flexural Strength; Slump Value