الفهرس 
CementsOnly 14 pages are availabe for public view
 |  | from | 110 |  |  |
| | | from | 110 | | |
Abstract
This work focuses on evaluating the performance of cementitious materials prepared by mixing alkaline source (lime rich sludge; LRS or magnesium oxide; MgO) with different silicate-rich-wastes (glass waste powder; GWP, ceramic waste powder; CWP, and lead bearing glass sludge; LBGS). This study includes two main parts:
The first part relates mainly to preparation and hydration characteristics of eco-friendly cements from pozzolanic materials and LRS. Bricks were prepared from mixing LRS (alkaline source), GWP and CWP (silicate-rich wastes). These wastes were individually activated by different LRS weight ratios of (90:10, 70:30, and 50:50) silicate-waste to LRS. The results demonstrated that, compressive strength (FCompression), water absorption (WA), and bulk density (BD) of the hardened materials mainly depend on LRS-content and pozzolanic waste type. For GWP-LRS mixtures the use of 30 Wt., % LRS results in the optimum compressive strength values at all curing ages up to 90 days. While for CWP-LRS bricks, the 50 Wt.,% LRS gave the higher compressive strength values.
The second part focused on LBGS-stabilization using reactive magnesia (MgO) via the fabrication of lightweight building bricks. Two types of MgO with different reactivities were prepared by the thermal treatment of magnesium carbonate at 800 and 1200°C (MgO800° and MgO1200°, respectively). The fabrication of bricks and Pb-cations stabilization were performed by wet mixing LBGS with MgO followed by humidity incubation. The results showed that, Pb-cations immobilization and performance of the produced bricks were strongly effected by curing time, MgO-reactivity, and LBGS-MgO weight ratios. Pb-cations immobilization was performed by the transformation of soluble lead into insoluble hydrocerussite phase [Pb3(CO3)2(OH)2], particularly in hydrated mixtures with high MgO content (˃ 25 Wt.,%). Pb-cations immobilization inside a magnesium silicate hydrate (MSH) skeleton is the acceptable incubation mechanism for the hydrated samples containing 25 Wt.,% MgO.
To achieve “sustainability”, we recommend the use of a hydrated mixture containing 75 Wt.,% LBGS and 25 Wt.,% MgO800° in the production of building bricks, because this mixture exhibits high compressive strength, high Pb-cations immobilization, low energy demand