London South Bank University, UK.
Highway Design & Maintenance, Environment & Infrastructure, Hertfordshire County Council, UK.
Waste Manag Res. 2021 Mar;39(3):466-472. doi: 10.1177/0734242X20983890. Epub 2021 Feb 3.
Pulp and paper manufacturing and recycling industries are a resource-intensive sector, generating 25-40% of the annual municipal solid waste worldwide. Waste includes abundant volumes of paper sludge, as well as the product of its incineration, namely paper sludge ash. These two waste materials are both predominantly landfilled. There is thus a drive for additional valorisation routes for these materials. This short communication focuses on the potential use of paper sludge ash in alkali-activated cement concrete; this type of concrete was estimated to potentially reduce CO emissions by up to 5-6 times, while it can also incorporate waste materials or industrial by-products in its composition. The paper presents a laboratory study assessing the feasibility of structural alkali-activated cement concrete with ground granulated blastfurnace slag (a by-product of steel production) and paper sludge ash. Paper sludge ash is used mainly as a source of Ca(OH) in the alkaline activator solution, and secondly as an additional source of aluminosilicates. A number of factors potentially affecting the activation process and the resulting concrete quality were investigated, including different dosage of activators, curing conditions and curing time. Mixes with paper sludge ash in the activator system developed high early concrete strengths at ambient temperatures and maintained adequate strengths for structural concrete. Further mix optimisation and mechanical and durability testing, accompanied by material characterisation, are required to establish the advantages of using this waste material in structural alkali-activated cement concrete.
制浆造纸和回收工业是一个资源密集型行业，每年产生全球 25-40%的城市固体废物。废物包括大量的纸污泥，以及其焚烧的产物，即纸污泥灰。这两种废物主要都是填埋处理。因此，需要寻找这些材料的其他增值途径。本简讯重点介绍了纸污泥灰在碱激活水泥混凝土中的潜在用途；这种类型的混凝土估计可以将 CO 排放量减少 5-6 倍，同时还可以在其组成中纳入废材料或工业副产品。本文介绍了一项实验室研究，评估了使用磨细粒化高炉矿渣（钢铁生产的副产品）和纸污泥灰的结构碱激活水泥混凝土的可行性。纸污泥灰主要用作碱性激发剂溶液中 Ca(OH)的来源，其次是作为额外的铝硅酸盐来源。研究了许多可能影响激活过程和混凝土质量的因素，包括不同的激活剂用量、养护条件和养护时间。在开发的激活剂系统中加入纸污泥灰的混合物在环境温度下具有较高的早期混凝土强度，并保持了结构混凝土所需的足够强度。需要进一步进行配合比优化和机械及耐久性测试，并进行材料特性分析，以确定在结构碱激活水泥混凝土中使用这种废材料的优势。
