Zhang Lu, Zhang Yilong, Zhang Fan, Liang Haonan, Niu Ditao, Li Hui
College of Materials Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
School of Architecture and Construction, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Materials (Basel). 2024 Dec 30;18(1):109. doi: 10.3390/ma18010109.
Magnesium slag is a by-product of the magnesium industry. As an auxiliary cementitious material incorporated into concrete, it can make full use of waste resources and has a certain potential for hydration and carbonation. To improve the mechanical properties of the concrete, the influence mechanism and strengthening mechanism of the carbon curing method on mechanical properties of magnesium slag concrete were investigated. The effects of different magnesium slag content and water-cement ratio on mechanical properties and ecological properties of carbon cured magnesium slag concrete were analyzed. Based on the phase composition and thermogravimetric composition of magnesium slag concrete, the carbonation mechanism of magnesium slag was revealed. The mechanical properties models of magnesium slag concrete with different carbon curing were constructed. The study shows that with the increase of the magnesium slag, the mechanical properties of carbon curing concrete first increase and then decrease. The optimum mechanical properties of concrete are 30% magnesium slag, and the compressive strength reaches 42.3 MPa. The content of magnesium slag increased from 0% to 60%, and the carbon fixation content was 14.60%, 11.87%, 11.69%, 16.90%, 19.80%, 14.78%, and 13.09%, respectively. With the increase of magnesium slag content, the content and grain size of magnesium oxide in concrete increase, which leads to more micro-bumps and depressions on the surface of the concrete structure. The hydration reaction and carbonation reaction of gelled materials are affected by magnesium ions, resulting in changes in the morphology and crystal structure of CaCO and MgCO reactants.
镁渣是镁工业的副产品。作为一种掺入混凝土中的辅助胶凝材料，它能够充分利用废弃资源，并且具有一定的水化和碳化潜力。为提高混凝土的力学性能，研究了碳化养护方法对镁渣混凝土力学性能的影响机理和增强机理。分析了不同镁渣掺量和水灰比对碳化养护镁渣混凝土力学性能和生态性能的影响。基于镁渣混凝土的物相组成和热重组成，揭示了镁渣的碳化机理。构建了不同碳化养护条件下镁渣混凝土的力学性能模型。研究表明，随着镁渣掺量的增加，碳化养护混凝土的力学性能先提高后降低。混凝土力学性能最佳时的镁渣掺量为30%，抗压强度达到42.3MPa。镁渣掺量从0%增加到60%时，混凝土中氧化镁的含量和粒径随之增加，导致混凝土结构表面出现更多的微凸起和凹陷。胶凝材料的水化反应和碳化反应受到镁离子的影响，致使CaCO和MgCO反应物的形态和晶体结构发生变化。
