Hydrophobic concrete using waste paper sludge ash

Abstract

8The feasibility of using a low-cost super hydrophobic powder as water-resisting admixture or water-repellent 9 surface coating for concrete has been investigated. The powder was produced from paper sludge ash (PSA), 10 a by-product from the manufacture of recycled paper. The effect of hydrophobic PSA on workability, 11 strength and transport properties, including sorptivity, water absorption, diffusivity, permeability and 12 electrical conductivity is reported. Samples were prepared at water/cement ratio of 0.38, cured up to 28 days 13 and conditioned at 50°C to constant mass prior to testing. It was found that replacing Portland cement with 14 12% hydrophobic PSA reduced water absorption, sorptivity and conductivity by 84%, 86% and 85% 15 respectively, with no major detrimental effects on hydration, strength and density. When used as a surface 16 coating, the hydrophobic PSA reduced both absorption and sorptivity by 85-99% depending on the adhesive 17 used. Samples surface coated with hydrophobic PSA showed excellent water repelling and self-cleaning 18 characteristics.19

Strength and Durability Assessment of Portland Cement Mortars Formulated from Hydrogen-Rich Water

“…Latex and calcium stearate are permeability reducers, which increase the impermeability of concrete materials to improve durability. Certain hydrophobic materials (water repellents) also tend to increase absorption 2 Advances in Materials Science and Engineering resistance and thereby the durability of concrete [8]. Water reducers and superplasticizers such as lignosulfonate and polycarboxylate also tend to improve the mechanical performance and durability of concrete by reducing the w/c ratio without affecting flowability [9].…”

Biopoliuretano putų, modifikuotų popieriaus gamybos atliekomis, tyrimai

“…Pastebėta, kad gerai kontroliuojamo degimo metu molingosios medžiagos, esančios PGAD sudėtyjekaolinitas -gali būti transformuojamos į metakaolinitą. Degtos PGAD atliekos taip pat pasižymi dideliu pucolaniniu aktyvumu, kuris yra apibrėžiamas kaip medžiagos gebėjimas reaguoti su portlanditu, dalyvaujant papildomam vandens kiekiui (García et al 2008), todėl tolimesnės PGAD panaudojimo galimybės buvo tirtos cemento bei keramikos gaminių gamyboje (Lin et al 2012;Martínez et al 2012), taip pat ir žemės ūkyje (Gallardo et al 2010;Gallardo et al 2012), ceolitų sintezėje (Bao et al 2016), sunkiųjų konstrukcijų (Cusidó et al 2015, Haddar et al 2016, vandeniui nelaidžių medžiagų (Wong et al 2015), lengvųjų konstrukcijų (Ferrándiz-Mas et al 2014;Sutcu, Akkurt 2009) bei absorbentų gamyboje (Jin et al 2015).…”

Use of steel slag and quartz sand‐tailing for the preparation of an eco‐friendly permeable brick

“…[9][10][11] Paper sludge ash from paper industry has been reported to be used as pozzolanic additives or to prepare hydrophobic concrete. 12,13 China, as a highly industrialized developing country, its ISW production per year is also very huge. It has been reported that, up to 2015, the total production of China's ISW has been reached 3.27 billion tons, while the comprehensive utilization rate of them was only 48%.…”