Use of ornamental rock waste as a partial substitute for binder in the production of structural concrete

Abstract Due to the population increase, to the improvement of life conditions, to the elevation of levels of consumption and the growing industrialization of developing countries, it is estimated that the production of concrete will present significant increase in the next decades. The process of producing cement is responsible for approximately 5 % of the emissions of CO2, an expressive environment pollutant. In this context, this work presents an evaluation of the influence of partial substitution of cement by ornamental rock waste (ORW) on the physical and mechanical properties of concrete. ORW from a local marble and granite processing company was used. The waste was mineralogically characterized through X-ray diffraction (XRD) essays, energy-dispersive X-ray (EDX) microanalysis, and physically characterized through laser granulometry and specific mass. For this, was adopted a concrete trace as reference, produced with CP V-ARI cement (similar to ASTM Type III), from IPT dosage. Waste was used in proportions of 5 %, 7.5 %, 10 % and 12.5 % of substitution of cement by mass. Results were treated with ANOVA and multiple comparison of means, indicating a possibility of substitution of until 10% of cement by ORW, creating a concrete with proper resistance to Brazilian regulations regarding the classification as structural.

摘要 伴随人口增长、生活条件改善、消费水平升级以及发展中国家工业化进程加速，预计未来数十年间混凝土产量将实现显著增长。水泥生产过程约贡献了5%的二氧化碳（CO₂）排放，而CO₂是一类主要的环境污染物。在此背景下，本研究针对饰面岩石废料（Ornamental Rock Waste，ORW）部分替代水泥对混凝土物理及力学性能的影响开展了评估。本研究采用某本地大理石与花岗岩加工企业产生的饰面岩石废料，通过X射线衍射（X-ray Diffraction，XRD）测试、能量色散X射线微区分析（Energy-dispersive X-ray，EDX）完成了废料的矿物学表征，并借助激光粒度分析法与比质量测试实现了其物理性能表征。为开展试验，本研究采用了IPT制定的混凝土基准配合比，该配合比以CP V-ARI水泥（性能等同于美国材料与试验协会ASTM III型水泥）配制而成；试验中以质量为基准，分别采用5%、7.5%、10%及12.5%的替代率，用饰面岩石废料替代水泥。研究采用方差分析（Analysis of Variance，ANOVA）与均值多重比较法对试验结果进行处理，结果表明：饰面岩石废料替代水泥的最高可行替代率可达10%，所配制的混凝土强度符合巴西规范中结构用混凝土的分类要求。