| Title |
Enhancement of engineering properties of cement mortars with masonry construction and demolition fines via carbon dioxide utilization, storage and chemical treatment |
| ID_Doc |
15007 |
| Authors |
Dwivedi, A; Bollam, R; Gupta, S |
| Title |
Enhancement of engineering properties of cement mortars with masonry construction and demolition fines via carbon dioxide utilization, storage and chemical treatment |
| Year |
2024 |
| Published |
|
| DOI |
10.1016/j.conbuildmat.2024.137355 |
| Abstract |
Shortage of natural sand is severely affecting the global construction industry. The construction sector also generates a substantial amount of construction and demolition (C &D) waste of which masonry wastes constitute a major fraction. Using a circular economy approach, this article explores the feasibility of using treated masonry waste fines (MWF) to replace 75 % of natural sand in Portland cement-based mortars. The treatment consists of a combination of acid washing and CO 2 curing to improve the engineering properties of MWF-cement mortars. 0.1 mol/L and 0.5 mol/L (M) H 2 SO 4 were used for chemical treatment of the MWF followed by CO 2 curing at 50,000 ppm for 4 hours. Mortars containing treated MWF (MWF-0.1 M-C and MWF-0.5 M-C) were subject to conventional curing (moist curing followed by dry curing at 30 degrees C and 65 % RH) and carbon sequestration via accelerated carbonation curing. Experimental findings suggest that combined treatment with acid and CO 2 reduces the pore volume by 13 - 27 % in the pore size range of 10 - 100 nm in MWF. Consequently, mortars with MWF-0.1 M-C and MWF-0.5 M-C show 29 - 30.50 % higher compressive strength at 28-d age and a 29 - 36 % reduction in total shrinkage compared to mortars with similar dosages of as-received MWF. This ensures statistically similar strength and shrinkage as that of the plain mortar (with 100 % natural sand), demonstrating the potential for 75 % sand replacement using treated MWF. Furthermore, carbon sequestration of 16.40 - 19 % by mass of Portland cement is achieved, which contributes to a 15 % enhancement in early strength and reduces the mesoporous volume and shrinkage by up to 43 % and 15-19 % respectively. In summary, the research offers a pathway to recover a "new sand" from C &D wastes , which could be used to manufacture masonry construction products with reduced demand for natural sand. |
| Author Keywords |
Mortar; Carbon dioxide utilization; Carbon Sequestration; Construction and demolition wastes; Shrinkage |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:001298685200001 |
| WoS Category |
Construction & Building Technology; Engineering, Civil; Materials Science, Multidisciplinary |
| Research Area |
Construction & Building Technology; Engineering; Materials Science |
| PDF |
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