Model development.

The recycling of waste materials as environmentally friendly cement alternatives to lessen the impact of CO2 emissions and safeguard natural resources associated with cement manufacturing cannot be over-emphasized. This study investigates the effects of recycled waste materials such as shea nutshell ash and ground oyster seashell as Portland limestone cement substitutes on the mechanical, durability, and sustainability performances of ternary blended concrete. Shea nutshell ash and ground oyster seashell were partially used as cement replacement at 5–15 wt. % and tested for mechanical properties after 3–120 curing ages. Chemical resistances and drying shrinkage were conducted as durability performance after 120 and 1–120 curing ages. The results revealed higher compressive, flexural, and split tensile strengths at later ages, with about a 3% increase at 10 wt. % substitution after 90 curing ages than the control concrete. Ternary blended concrete samples, at 5–10 wt. % of shea nutshell ash and ground oyster seashell replacement levels, resulted in improved acidic, sulfate, and drying shrinkage resistances by 11–40%, 12–53%, and 9–34%, compared to the control samples. Ultimately, this research recommends an optimum of 10 wt. % shea nutshell ash and ground oyster seashell as cement alternatives, enhancing mechanical durability properties of ternary blended concrete.

以废弃材料作为环保型水泥替代原料，以降低二氧化碳排放影响、保护水泥生产相关的自然资源，其重要性无论如何强调都不为过。本研究探究了乳木果壳灰（shea nutshell ash）与磨碎牡蛎壳（ground oyster seashell）等废弃再生材料作为波特兰石灰石水泥（Portland limestone cement）替代原料时，对三元复合混凝土（ternary blended concrete）力学性能、耐久性能与可持续性能的影响。研究中以5~15 wt%的掺量将乳木果壳灰与磨碎牡蛎壳作为部分水泥替代原料，并在3~120 d养护龄期下测试其力学性能；分别在120 d与1~120 d养护龄期下开展化学耐蚀性与干燥收缩测试，以评估其耐久性能。测试结果显示，后期养护龄期下的试样具备更优的抗压、抗折与劈裂抗拉强度：在90 d养护龄期、10 wt%掺量的替代条件下，其强度较基准混凝土提升约3%。当乳木果壳灰与磨碎牡蛎壳的掺量为5~10 wt%时，三元复合混凝土试样的酸性耐蚀性、硫酸盐耐蚀性与干燥收缩抗性较基准试样分别提升11%~40%、12%~53%与9%~34%。综上，本研究推荐以10 wt%的乳木果壳灰与磨碎牡蛎壳作为最优水泥替代原料，可有效改善三元复合混凝土的力学与耐久性能。