Fresh Properties of Low-Carbon Cement Pastes Incorporating Industrial By-Products

Abstract

Cement production involves limestone decarbonation and fuel consumption, making it responsible for almost 10% of worldwide CO2 emissions that worsen the effects related to global warming. Consequently, finding alternative types of cement to reduce clinker dependence has become urgent, and this is one of the most important research fields in civil construction materials. Limestone-calcined clay cement (LC3) is a strategy to reduce CO2 emissions in the cement industry since incorporating supplementary cementitious materials (SCM) from various industries into LC3 mixtures can reduce even more CO2 emissions. This study investigates the properties of the fresh state of cement pastes incorporating silica fume, fly ash, and sugarcane bagasse ash, resulting LC3 a quaternary mixture. Fine materials were characterized by modified Chapelle method, scanning electron microscopy (SEM) and x-ray fluorescence (XRF). Cement pastes had setting time, minislump, and Marsh funnel tests performed at fresh state. Thermogravimetry (TGA) and x-ray diffraction (XRD) at 7 and 28 days were performed to analyze the pozzolanic activity, and superplasticizer dosage effects were investigated in the pastes. The results indicated that LC3 mixtures showed longer setting time and higher superplasticizer consumption concerning portland cement reference paste. Spherical particle incorporation improves the pastes’ flowability and reduces superplasticizer consumption, so fly ash presented the best global performance for the fresh properties of LC3.