Geopolymers produced with metakaolin (MK) and thermally untreated phosphate sludge (PS) are beneficial and environmentally advantageous materials, but their fragility limits its applications. The present research aims to evaluate the influence of polypropylene fibers PPF inclusion in MK/PS based geopolymers in view of overcoming the brittleness of these materials. The geopolymer matrix was prepared by mixing the thermally untreated phosphate sludge with the metakaolin in a proportion of 50% by weight, then short polypropylene fibers (PPFs) as reinforcement material were incorporated in amounts of 0.25, 0.50, 1, and 1.5%. Composite performances were assessed in the fresh state through flow measurement, and in the hardened state through the properties of the composites under bending and compressive loading conditions. In addition, the fiber/matrix interfacial contact area was examined using scanning electron microscopy (SEM). The outcomes demonstrate that the PPF incorporation of up to 1.5% by weight into MK/PS based geopolymer paste significantly improves the flexural strength with an increase of 41% (6.41 and 9.62 MPa), as well as leads to a slight decrease of compressive strength and density. The findings of the current research reveals also that MK/PS based geopolymers can achieve a high ductility with an adequate reinforcement.

Graphical Abstract

中文翻译：

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基于聚丙烯纤维增强的非热处理磷酸盐污泥的环保型地质聚合物复合材料

用偏高岭土（MK）和未经热处理的磷酸盐污泥（PS）生产的地聚合物是有益和对环境有利的材料，但其易碎性限制了其应用。鉴于克服了这些材料的脆性，本研究旨在评估聚丙烯纤维PPF包含在基于MK / PS的地质聚合物中的影响。通过将未经热处理的磷酸盐污泥与偏高岭土以50重量％的比例混合来制备地聚合物基体，然后以0.25％，0.50％，1％和1.5％的量掺入作为增强材料的短聚丙烯纤维（PPF）。在流动状态下通过流量测量评估了复合材料的性能，在弯曲和压缩负载条件下，通过复合材料的性能评估了其在硬化状态下的性能。此外，使用扫描电子显微镜（SEM）检查纤维/基质界面接触面积。结果表明，PPF掺入量高达1.5％（重量）到基于MK / PS的地质聚合物浆料中，弯曲强度显着提高，增加了41％（6.41和9.62 MPa），并且导致抗压强度略有下降。和密度。当前研究的结果还表明，基于MK / PS的地质聚合物可以在具有足够的增强作用的情况下实现高延展性。并导致抗压强度和密度略有下降。当前研究的结果还表明，基于MK / PS的地质聚合物可以在具有足够的增强作用的情况下实现高延展性。并导致抗压强度和密度略有下降。当前研究的结果还表明，基于MK / PS的地质聚合物可以在具有足够的增强作用的情况下实现高延展性。

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