Influence of Waste Glass Powder Addition on the Microstructure and Mechanical Properties of Autoclaved Building Materials

Abstract

Lime quartz samples in which ground quartz sand was gradually substituted with waste glass powder (GP) were obtained under hydrothermal conditions to determine the influence of GP addition on the microstructure (observed by SEM), phase composition (analyzed by XRD), and compressive strength of autoclaved building materials. An additional series containing analytical grade NaOH and no GP was formed to evaluate the effect of sodium ions on tobermorite formation and its impact on the mechanical properties of the samples. GP addition hindered the formation of tobermorite during autoclaving. Instead, a higher amount of an amorphous and semi-crystalline C–S–H phase formed, leading to the densification of the composite matrix. Nevertheless, tobermorite-like structures were found during both XRD and SEM analyses, proving that the presence of small amounts of Al3+ ions allowed, to an extent, for the stabilization of the phase despite the high sodium content. The compressive strength values indicate that the presence of alkali in the system and the resulting formation of additional portions of C–S–H have a beneficial influence on the mechanical properties of autoclaved composites. However, the effect fades with increasing glass powder content which, together with a slight expansion of the samples, suggests that at high sand substitution levels, an alkali–silica reaction takes place.

Environmentally friendly material solutions in the technology of autoclaved aerated concrete

“…The source of silica can also be various other materials, e.g. burnt coal shale ( 16), glass cullet (24), metallurgical slag and municipal waste ash (25). Especially the latter are more and more often the subject of research, due to the constantly increasing amount of waste generated, especially in large cities, and the problems with its disposal.…”

Influence of Waste Basalt Powder Addition on the Microstructure and Mechanical Properties of Autoclave Brick

“…An example of such a solution is the use of ground chalcedonite [ 24 , 25 ], ground limestone [ 26 ], dolomite powder [ 27 ], metakaolinite [ 28 ], barium [ 29 ], bentonite [ 30 ], thermally activated Carboniferous shale [ 31 ] and silica fume [ 32 ]. In recent years, the impact of waste glass in silicates has been extensively studied [ 33 , 34 , 35 , 36 , 37 ].…”

Influence of Recipe Factors on the Structure and Properties of Non-Autoclaved Aerated Concrete of Increased Strength

“…In particular, not only the technological process of obtaining aerated concrete is complex, but also the technological line itself, which often consists of more expensive equipment. In this regard, the most high-quality, but at the same time the most expensive, type of cellular concrete is the so-called gas silicate or autoclaved aerated concrete [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”