Abstract

The aim of this study is to demonstrate the effectiveness of cement admixtures in improving the shrinkage and strength resistance of EPS lightweight concretes (ELCs). A group of EPS mixtures containing 0.5, 1 and 2% of sodium alginate, 0.1, 0.3 and 0.5% of xanthan gum and 2, 5 and 8% of diatomite was used. The results of the study showed that increasing the dose of each admixture significantly improved the strength and shrinkage resistance of ELC. Although the application of sodium alginate, xanthan gum and diatomite as cement admixtures decreased the water loss ratio of EPS concrete compared to the reference mix, the increase in their contents increased the water loss ratio of EPS concrete. The increase in sodium alginate, xanthan gum and diatomite content improved the EPS concrete pore structure stability and performance of the interface of transition zones (ITZ) between the cement slurries and EPS aggregates, which had a positive role in improving the strength and shrinkage behaviour of ELC. Application of 2% sodium alginate, 0.5% of xanthan gum and 8% of diatomite can be recommended as the preferred dose of cement admixtures to improve the strength and shrinkage performance of ELC.

摘要

本研究的目的是证明水泥外加剂在提高 EPS 轻质混凝土 (ELC) 的收缩性和抗强度方面的有效性。使用一组含有0.5%、1%和2%的海藻酸钠、0.1%、0.3%和0.5%的黄原胶以及2%、5%和8%的硅藻土的EPS混合物。研究结果表明，增加每种外加剂的用量显着提高了ELC的强度和抗收缩性。虽然与参考配合比相比，海藻酸钠、黄原胶和硅藻土作为水泥外加剂的应用降低了EPS混凝土的失水率，但它们含量的增加增加了EPS混凝土的失水率。海藻酸钠的增加，黄原胶和硅藻土含量提高了EPS混凝土孔隙结构的稳定性和水泥浆与EPS骨料之间过渡区（ITZ）界面的性能，对提高ELC的强度和收缩性能具有积极作用。推荐应用2%海藻酸钠、0.5%黄原胶和8%硅藻土作为水泥外加剂的优选掺量，以提高ELC的强度和收缩性能。