This article explores fortifying cement mortars against severe sulfuric acid (SLA) attacks by studying the impact of nano-SiO2 (NS), macro-steel (ST), and micro-polypropylene (PP) fibers. The aim is to assess their effects on workability, physical attributes, mechanical properties, and durability against SLA attacks when incorporated into mortar blends. Replacing 1 % of cement weight with NS, having average particle diameters of 15 nm (nm) (NS15) and 55 nm (NS55), and utilizing macro-ST and micro-PP fibers at volumes of 0.5 % and 1 % in singular and hybrid forms resulted in significant changes in mortar characteristics. While these additives increased fresh mortar viscosity and negatively affected workability, they substantially boosted mortar strength and durability against SLA attacks. The most substantial improvements were observed using smaller NS particle sizes and employing hybrid ST/PP fibers. The formation of calcium-silicate-hydrate (C-S-H) bonds by NS within the network emerged as a pivotal factor. NS's high pozzolanic activity and void-filling capacity significantly enhanced the mortars' strength and durability against SLA attacks. Furthermore, instead of their singular application, the combined use of ST and PP fibers proved more effective in restraining micro and macro cracks within the mortar matrix. The bridging effect of hybrid ST/PP fibers delayed crack propagation throughout the network, highlighting their superior efficiency against SLA attacks.

中文翻译：

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增强水泥砂浆的弹性：研究纳米 SiO2 尺寸和杂化纤维对耐硫酸性的影响


本文通过研究纳米 SiO2 （NS）、宏钢 （ST） 和微聚丙烯 （PP） 纤维的影响，探讨了强化水泥砂浆抵御严重的硫酸 （SLA） 侵蚀。目的是评估它们在掺入砂浆混合物中时对可加工性、物理特性、机械性能和耐久性的影响，以抵御 SLA 侵蚀。用平均粒径为 15 nm （nm） （NS15） 和 55 nm （NS55） 的 NS 代替 1% 的水泥重量，并使用体积为 0.5% 和 1% 的单一和混合形式的宏观 ST 和微 PP 纤维，导致砂浆特性发生显着变化。虽然这些添加剂增加了新砂浆的粘度并对施工性能产生了负面影响，但它们大大提高了砂浆的强度和耐久性，抵御 SLA 攻击。使用较小的 NS 粒径和采用混合 ST/PP 纤维观察到最显着的改进。NS 在网络内形成钙-硅酸盐-水合物 （CS-H） 键成为一个关键因素。NS 的高火山灰活性和空隙填充能力显着增强了迫击炮对 SLA 攻击的强度和耐久性。此外，事实证明，ST 和 PP 纤维的联合使用在抑制砂浆基体中的微观和宏观裂缝方面更有效，而不是它们的单一应用。混合 ST/PP 光纤的桥接作用延迟了整个网络中的裂纹传播，凸显了它们对 SLA 攻击的卓越效率。