Mechanical and Physical Properties of Hydrophobized Lightweight Aggregate Concrete with Sewage Sludge

Abstract

This article is focused on lightweight aggregate-concrete modified by municipal sewage sludge and lightweight aggregate-concrete obtained from light aggregates. The article presents laboratory examinations of material physical parameters. Water absorptivity of the examined material was decreased by the admixture of water emulsion of reactive polysiloxanes. Water transport properties were determined using Time Domain Reflectometry, an indirect technique for moisture detection in porous media. Together with basic physical parameters, the heat conductivity coefficient λ was determined for both types of lightweight aggregate-concrete. Analysis of moisture and heat properties of the examined materials confirmed the usefulness of light aggregates supplemented with sewage sludge for prospective production.

Evaluation of the Contact Angle of Hydrophobised Lightweight-Aggregate Concrete with Sewage Sludge

“…Later, the samples were kept in constant laboratory conditions to fulfil the period of 28 days of maturing to be ready for further examinations. The exact characteristics of the sewage sludge and the lightweight aggregate were presented by the authors of this article in publication [10]. The tested material used for production of lightweight aggregate was sewage sludge taken from the municipal wastewater treatment plant "Hajdow" in Lublin and clay.…”

“…The sewage sludge from the wastewater treatment plant used for production of the lightweight aggregate was characterised by 80.43% moisture, 750 mg CaCO 3 3 density. Analysis of the content of heavy metals in the sewage sludge indicated presence of 1.539 ppm of cadmium, 14 ppm of chromium, 8.1 ppm of nickel, and 4.9 ppm of lead ions [10].…”

“…It should be mentioned here that sewage sludge from large municipal wastewater treatment plants containing eg heavy metals will not necessarily be suitable for the use in land application and agriculture [7]. In such a case, one of the ways of utilisation of this type of sewage sludge involves application thereof for production of building materials eg lightweight aggregate [8][9][10], in which it serves a function of a bulking agent and contributes to the highly porous texture of sintered ceramics. Lightweight aggregate can be used to produce energy-efficient [11][12][13], ecological lightweight-aggregate concrete blocks for building construction.…”

“…Lightweight-aggregate concrete modified with sewage sludge and used for production of energy-efficient blocks is characterised by higher porosity and water absorption capacity than its commercial counterpart, which is related to the porous structure of lightweight aggregate containing sewage sludge [10]. This poses a major problem while designing the composition of lightweight-aggregate concrete mixes.…”

Use of Spent Zeolite Sorbents for the Preparation of Lightweight Aggregates Differing in Microstructure

“…Many waste materials, such as combustion ashes [19], waste glass [15], sewage or industrial sludge [20][21][22][23], incinerator bottom ash [24], mining residues, heavy metal sludge, washing aggregate sludge [4], polishing residue, lignite coal fly ash [25,26], spent adsorbents [27,28] and contaminated mine soil [29], have been used as additives for the production of LWAs. Some of…”