CO2 Uptake and Physicochemical Properties of Carbonation-Cured Ternary Blend Portland Cement–Metakaolin–Limestone Pastes

Abstract

The feasibility of carbonation curing of ternary blend Portland cement–metakaolin–limestone was investigated. Portland cement was substituted by the combination of metakaolin and limestone at levels of 15%, 30%, and 45% by the mass. The ternary blends were cured with four different combinations of ambient and carbonation curing. The mechanical property, CO2 uptake, and mineralogical variations of the ternary blend pastes were investigated by means of compressive strength test, thermogravimetric analysis, and X-ray diffractometry. In addition, volume of permeable voids and sorptivity of the ternary blends were also presented to provide a fundamental idea of the pore characteristics of the blends. The test results showed that the increasing amount of metakaolin and limestone enhanced the CO2 uptake, reaching 20.7% for the sample with a 45% cement replacement level at 27 d of carbonation. Meanwhile, the compressive strength of the samples was reduced up to 65% upon excessive incorporation of metakaolin and limestone. The samples with a replacement level of 15% exhibited a comparable strength and volume of permeable voids to those of the sample without substitution, proving that the ternary blend Portland cement–metakaolin–limestone can be a viable option toward the development of eco-friendly binders.

Optimization of an Eco-Friendly Hydraulic Road Binders Comprising Clayey Dam Sediments and Ground Granulated Blast-Furnace Slag

“…A + F + 8 CH + 18 H → C 8 AFH 26 (7) where CH = Portlandite, S = SiO 2 , A = Al 2 O 3 , F = Fe 2 O 3 , and H = H 2 O. The two road binders fall into the class of normal hardening hydraulic road binder (class N4 binders) according to EN 13282-2, which states that the UCS after 56 days of curing is between 32.5 MPa and 52.5 MPa.…”

“…Cement production is responsible for the emission of one ton of CO 2 for each ton of produced clinker [4][5][6]. It generates a global greenhouse gas emission amount of 5 to 8% of the entire CO 2 emissions [6,7]. This is due to its high energy process (i.e., clinkerization process at 1450 • C), which produces an equivalent energy of about 3.5 GJ per 1 ton of Portland cement clinker [8,9].…”

“…This is due to its high energy process (i.e., clinkerization process at 1450 • C), which produces an equivalent energy of about 3.5 GJ per 1 ton of Portland cement clinker [8,9]. Two thirds of these emissions are due to the calcination of limestone (CaCO 3 ) and decomposition to calcium oxide (CaO), while the remaining third of these emissions are attributed to fossil fuel combustion [7,9,10]. Therefore, this has become a major environmental, industrial, and societal concern.…”

Model-Based Methods to Produce Greener Metakaolin Composite Concrete

“…The sustainability of concrete depends on many indexes, such as CO 2 emissions, energy consumption, and resource consumption [32]. The CO 2 emissions of concrete, T CO 2 , can be determined as the sum of individual components [33][34][35][36][37] as follows:…”

Investigating the performance of ternary cementitious systems incorporating wollastonite powder and lime sludge in concrete

“…SCMs are materials that can partially replace traditional cement in concrete production.By doing so, the energy consumed and the greenhouse gas emissions linked to cement manufacturing can be decreased. Common SCMs include fly ash, slag, lime Sludge, wollastonite, and silica fume, waste products from industrial processes [7]. These materials can enhance strength, durability, and workability and reduce the cement content needed [8].…”