Compressive and Thermal Properties of Non-Structural Lightweight Concrete Containing Industrial Byproduct Aggregates

Abstract

This study aimed to investigate the recycling opportunities for industrial byproducts and their contribution to innovative concrete manufacturing processes. The attention was mainly focused on municipal solid waste incineration fly ash (MSWI-FA) and its employment, after a washing pre-treatment, as the main component in artificially manufactured aggregates containing cement and ground granulated blast furnace slag (GGBFS) in different percentages. The produced aggregates were used to produce lightweight concrete (LWC) containing both artificial aggregates only and artificial aggregates mixed with a relatively small percentage of recycled polyethylene terephthalate (PET) in the sand form. Thereby, the possibility of producing concrete with good mechanical properties and enhanced thermal properties was investigated through effective PET reuse with beneficial impacts on the thermal insulation of structures. Based on the obtained results, the samples containing artificial aggregates had lower compressive strength (up to 30%) but better thermal performance (up to 25%) with respect to the reference sample made from natural aggregates. Moreover, substituting 10% of recycled aggregates with PET led to a greater reduction in resistance while improving the thermal conductivity. This type of concrete could improve the economic and environmental aspects by incorporating industrial wastes—mainly fly ash—thereby lowering the use of cement, which would lead to a reduction in CO2 emissions.

Physical, Mechanical, and Microstructure Characteristics of Ultra-High-Performance Concrete Containing Lightweight Aggregates

“…The sample with 0% LWA had the highest mass percentage at all corresponding temperatures, indicating that the absence of lightweight aggregates leads to a denser UHPC mixture. On the other hand, the sample with 30% LWA had the lowest mass percentage compared to LW0 and LW15 across all curing days, indicating that a high percentage of LWAs leads to a less dense UHPC mixture [ 86 ].…”

Influence of Unidirectional Cyclic Loading on Bond between Steel Bars Embedded in Lightweight Aggregate Concrete

“…The relative displacement between the unloaded end of the bar and the related concrete surface normal to it is directly measured during the test and assumed as equal to the slip (s) value according to Equation (2). Having the τ b -s relationship, the bond strength (τ bu ) is represented as the maximum value of bond stress.…”

“…The simplest way to decrease the self-weight of concrete is to change the normal weight aggregate to lightweight aggregate (tuff, expanded clay, etc.). Lightweight aggregates are widely used for non-structural purposes due to their advantageous thermal properties [2,3]; however, structural applications of lightweight aggregate concrete come to the front for self-weight dominant structures, in case of which the contribution of self-weight in the total action effect exceeds 50-60%. The combination of high-strength lightweight aggregate concrete (>LWAC50/55) with prestressing is a perspective area in the field of high-capacity prefabricated (bridge) girders that may open the door for structural lightweight aggregate concretes towards their application in industrial scale.…”

Effect of accelerated aging and silica fume addition on the mechanical and microstructural properties of hybrid textile waste-flax fabric-reinforced cement composites

“…Recyclability and CO 2 emissions are considered to be some of the main indicators of environmental sustainability in fiber/textile reinforced mortars (FRM/TRM) [1,2]. To develop more sustainable cementitious building materials, waste and recycled sources, as well as low carbon-embodied materials, are currently being used [3][4][5][6].…”