Performance of Fly Ash-Based Inorganic Polymer Mortar with Petroleum Sludge Ash

Petroleum sludge is a waste product resulting from petroleum industries and it is a major source of environmental pollution. Therefore, developing strategies aimed at reducing its environmental impact and enhance cleaner production are crucial for environmental mortar. Response surface methodology (RSM) was used in designing the experimental work. The variables considered were the amount of petroleum sludge ash (PSA) in weight percent and the ratio of sodium silicate to sodium hydroxide, while the concentration of sodium hydroxide was kept constant in the production of geopolymer mortar cured at a temperature of 60 °C for 20 h. The effects of PSA on density, compressive strength, flexural strength, water absorption, drying shrinkage, morphology, and pore size distribution were investigated. The addition of PSA in the mortar enhanced the mechanical properties significantly at an early age and 28 days of curing. Thus, PSA could be used as a precursor material in the production of geopolymer mortar for green construction sustainability. This study aimed to investigate the influence of PSA in geopolymer mortar.

The effect of curing on compressive strength of geo-polymer mortar made rice straw ash, fly ash, and laterite soil

This study aims to analyze the effect of curing on the compressive strength of geopolymer mortar made from straw ash, fly ash and laterite soil. This research is experimental in the laboratory. Geopolymer mortar was produced using straw ash, fly ash and laterite soil with a percentage ratio of 16.67: 41.67: 41.67. The alkaline activator used is sodium hydroxide (NaOH) with a concentration of 12 M. The compressive strength test of 5 × 10 cm cylinders is used to evaluate the geopolymer mortar mixture produced at the age of 3, 7 and 28 days with curing, namely air and water curing. The results showed that the compressive strength of the geopolymer mortar increased along with the increasing age of each curing. The compressive strength values produced in air curing 3, 7 and 28 days were respectively 1.64 N/mm2, 1.72 N/mm2 and 3.22 N/mm2. While water curing, the resulting compressive strength values for each curing are 1.03 N/mm2, 1.63 N/mm2 and 1.68 N/mm2. At the ages of 3, 7 and 28 days, there was an increase in the compressive strength values from water curing to air curing, which were 0.37%, 5.23% and 47.82%, respectively. It can be seen that the compressive strength of the geopolymer mortar made from straw ash, fly ash and laterite soil in air curing is greater than that of water curing.

Full-scale testing of adhesively bonded timber-concrete composite beams

This paper presents new findings on adhesively bonded timber-concrete composites with prefabricated concrete parts. Hereby, timber and concrete are bonded solely with adhesive and no metallic connectors have been used. Because the achievement of a continuous bond proved to be a critical point in past studies, special attention is given to that issue. The application procedure of the adhesives is investigated in small-scale bond samples and the manufacturing process in full-scale composite beams with a span of 8 m and a comparatively new polymer mortar is used as adhesive as well as a common epoxy resin. Both adhesives proved to be suitable, although polymer mortars showed strong advantages in terms of applicability and bridging of gaps in comparison to the less viscous epoxy adhesive. The full-scale beams are tested under quasi-static and cyclic loading. The failure occurred more as a bending failure of the timber or compression failure of the concrete. A full bond could be achieved at all full-scale beams. Moreover, an analytical and a finite element model for the calculation of composite beams are presented and validated. It could be seen, that both deformation behavior and failure load are in good accordance with the test results.