Ceramics based on concrete wastes prepared by spark plasma sintering
Ceramics based on concrete wastes prepared by spark plasma sintering
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DOI：
10.2298/pac2101100a
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发表时间：
2021
影响因子：
1.1
通讯作者：
M. Abass;Y. Kanda
中科院分区：
文献类型：
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作者：
M. Abass;Y. Kanda
需要一种有效的利用技术来回收混凝土废料中的细骨料，因为残余废水泥的存在会降低再生混凝土的质量。在这项研究中，通过研磨冲绳混凝土废料并使用放电等离子烧结（SPS）方法开发具有高抗弯强度的陶瓷压坯来制备再生骨料粉末（RAP）。 RAP原材料主要由方解石和石英组成。在1123-1273K烧结过程中，烧结体的致密化梯度是均匀的。在1273K的烧结温度下，维氏硬度（HV）最高达到393，最大抗弯强度为78.9MPa，超过了瓷质砖ISO 13006标准。扫描电子显微镜与能量色散X射线（SEM-EDX）元素分析表明，内部结构由未熔化的富硅砂颗粒和含有废水泥的熔化的富钙颗粒和石灰石细骨料组成。因此，可以得出结论，SPS是通过砂颗粒和富钙颗粒之间的液相烧结现象进行的，这有助于提高弯曲强度和模量。
An effective utilization technique is required to recycle fine aggregate in concrete waste because the presence of residual waste cement reduces the quality of the recycled concrete. In this study, recycled aggregate powder (RAP) was prepared by milling Okinawan concrete waste and developing a ceramic compact with high flexural strength using the spark plasma sintering (SPS) method. The RAP raw material consisted mainly of calcite and quartz. The densification gradient of the sintered compact was uniform during sintering at 1123-1273K. At 1273K sintering temperature, Vickers hardness (HV) obtained a maximum of 393 along with 78.9MPa maximum flexural strength, which exceeded the porcelain stoneware tile ISO 13006 standards. Scanning electron microscopy with energy dispersive X-ray (SEM-EDX) element analysis suggested that the inner structure constituted unmelted silica-rich sand particles and melted calcium-rich particles containing waste cement and fine aggregate with limestone. Therefore, it can be concluded that SPS progressed by the liquid-phase sintering phenomenon between sand particles and calcium-rich particles, which contributed to flexural strength and modulus improvement.