Stel'makh Sergey A, Beskopylny Alexey N, Shcherban' Evgenii M, Mailyan Levon R, Meskhi Besarion, Shilov Alexandr A, El'shaeva Diana, Chernil'nik Andrei, Kurilova Svetlana
Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia.
Department of Transport Systems, Faculty of Roads and Transport Systems, Don State Technical University, 344003 Rostov-on-Don, Russia.
Materials (Basel). 2023 Jun 15;16(12):4422. doi: 10.3390/ma16124422.
One of the most promising ways to solve the problem of reducing the rate of depletion of natural non-renewable components of concrete is their complete or partial replacement with renewable plant counterparts that are industrial and agricultural waste. The research significance of this article lies in the determination at the micro- and macro-levels of the principles of the relationship between the composition, the process of structure formation and the formation of properties of concrete based on coconut shells (CSs), as well as the substantiation at the micro- and macro-levels of the effectiveness of such a solution from the point of view of fundamental and applied materials science. The aim of this study was to solve the problem of substantiating the feasibility of concrete consisting of a mineral cement-sand matrix and aggregate in the form of crushed CS, as well as finding a rational combination of components and studying the structure and characteristics of concrete. Test samples were manufactured with a partial substitution of natural coarse aggregate with CS in an amount from 0% to 30% in increments of 5% by volume. The following main characteristics have been studied: density, compressive strength, bending strength and prism strength. The study used regulatory testing and scanning electron microscopy. The density of concrete decreased to 9.1% with increasing the CS content to 30%. The highest values for the strength characteristics and coefficient of construction quality (CCQ) were recorded for concretes containing 5% CS: compressive strength-38.0 MPa, prism strength-28.9 MPa, bending strength-6.1 MPa and CCQ-0.01731 MPa × m/kg. The increase in compressive strength was 4.1%, prismatic strength-4.0%, bending strength-3.4% and CCQ-6.1% compared with concrete without CS. Increasing the CS content from 10% to 30% inevitably led to a significant drop in the strength characteristics (up to 42%) compared with concrete without CS. Analysis of the microstructure of concrete containing CS instead of part of the natural coarse aggregate revealed that the cement paste penetrates into the pores of the CS, thereby creating good adhesion of this aggregate to the cement-sand matrix.
解决降低混凝土天然不可再生成分消耗率问题最有前景的方法之一，是用可再生的植物材料（即工农业废料）完全或部分替代它们。本文的研究意义在于，从微观和宏观层面确定基于椰壳（CS）的混凝土的组成、结构形成过程与性能形成之间的关系原理，以及从基础材料科学和应用材料科学的角度，在微观和宏观层面论证这种解决方案的有效性。本研究的目的是解决论证由矿物水泥砂基体和碎 CS 形式的骨料组成的混凝土的可行性问题，以及找到各组分的合理组合并研究混凝土的结构和特性。制备了试验样品，用 CS 以 5%的体积增量从 0%到 30%的量部分替代天然粗骨料。研究了以下主要特性：密度、抗压强度、抗弯强度和棱柱强度。研究采用了规范测试和扫描电子显微镜。随着 CS 含量增加到 30%，混凝土密度降低至 9.1%。含 5% CS 的混凝土的强度特性和施工质量系数（CCQ）最高：抗压强度为 38.0MPa，棱柱强度为 28.9MPa，抗弯强度为 6.1MPa，CCQ 为 0.01731MPa·m/kg。与不含 CS 的混凝土相比，抗压强度提高了 4.1%，棱柱强度提高了 4.0%，抗弯强度提高了 3.4%，CCQ 提高了 6.1%。与不含 CS 的混凝土相比，将 CS 含量从 10%增加到 30%不可避免地导致强度特性显著下降（高达 42%）。对用 CS 替代部分天然粗骨料的混凝土微观结构分析表明，水泥浆渗入 CS 的孔隙中从而使该骨料与水泥砂基体形成良好的粘结。
