Recycled powder (RP) is the main by-product in the reclamation of construction and demolition (CD in addition, improvement methods and a benefit evaluation of RP concrete are further introduced. Based on statistical data that describe the activity index of RP and the compressive strength of RP concrete, the median diameter and replacement ratio of RP in concrete preparation should be below 30 μm and 30%, respectively. The use of RP improves the durability of concrete when the RP fineness is superior to the cement fineness. Increasing the RP fineness is an effective approach to improving the properties of RP concrete, and a CO2-curing treatment of RCP is an eco-friendly modification method. Furthermore, the use of RP in concrete has good economic and environmental benefits. Therefore, one expects that this review helps the further use of RP in concrete.

The utilization of eco-friendly recycled powder from concrete and brick waste in new concrete: A critical review

The particle-size effect of waste clay brick powder on its pozzolanic activity and properties of blended cement

The sharply increasing solid waste generation has raised the environmental concerns worldwide which currently have been escalated to a worrying level. Intending to eliminate the negative environmental impacts of solid waste and meanwhile promote sustainability on the energy- and resource-intensive construction and building sector, considerable efforts have been devoted to recycling solid waste for the possible use in sustainable construction material products. This paper reviews the existing studies on recycling municipal and construction solid waste for the manufacture of geopolymer composites. Special attention is paid to the predominate performance of these geopolymer composite products. The principal findings of this work reveal that municipal and construction solid waste could be successfully incorporated into geopolymer composites in the forms of precursor, aggregate, additive, reinforcement fiber, or filling material. Additionally, the results indicate that although the inclusion of such waste might depress some of the attributes of geopolymer composites, proper proportion design and suitable treatment technique could alleviate these detrimental effects and further smooth the recycling progress. Finally, a brief discussion is provided to identify the important needs in the future research and development for promoting the utilization of solid waste materials in the forthcoming sustainable geopolymer industry. In summary, this work offers guidance for the better ecological choice to municipal and construction solid waste through developing waste materials into highly environmental-friendly construction materials.

Advanced progress in recycling municipal and construction solid wastes for manufacturing sustainable construction materials

Alkali-activated materials are a new class of compounds that have been studied by several authors worldwide. Alkali-activated binders can be competitive alternatives to traditional Portland cement, especially concerning CO2 emissions into the environment. However, in order to obtain this advantage, it is essential to use activators that were produced cleanly and sustainably, which is not the case of commercial products such as NaOH or sodium silicate. This paper provides a brief discussion about the activators traditionally used, and a review of existing literature about alternative activators, produced from agricultural or industrial wastes. Factors such as molar ratios and preparation of the solution were highlighted. The mechanical behavior of the pastes and mortars was also assessed, showing that the performance of alternative activators can be similar or even better than the conventional ones. Finally, some topics for future research on new activators were identified, aiming to stimulate more studies in this field.

Application of eco-friendly alternative activators in alkali-activated materials: A review

The use of waste brick powder (WBP) as supplementary cementitious material (SCM) provides an effective approach to reclaiming construction and demolition (CD when the WBP fineness is higher than the cement fineness, the compression strength with WBP contents up to 15% is superior to that without WBP, while the compression strength decreases with WBP incorporation when the WBP fineness is close to or lower than the cement fineness. Incorporating an appropriate WBP content decreases the water absorption of mortar, and the water absorption further decreases with increasing WBP fineness; for example, when the median diameter of WBP is 6 μm and 42 μm, the capillary absorption coefficient of mortar with 30% WBP is 34.1% lower and 10.3% higher than that of plain mortar, respectively. In addition, a similar conclusion is observed for the water distribution in WBP mortar.

Mechanical properties and water absorption of cement composites with various fineness and contents of waste brick powder from C&D waste

Application of waste brick powder in alkali activated aluminosilicates: Functional and environmental aspects

/pdf/microstructure-texture-and-mechanical-properties-of-2ndyeg7vfz.pdf

Nikol Alblová

Papers

Application of waste brick powder in alkali activated aluminosilicates: Functional and environmental aspects

Microstructure, texture, and mechanical properties of geopolymers prepared using industrial waste