Reuse of fly ash and bottom ash in mortars with improved thermal conductivity performance for buildings

Abstract

An approach towards effective utilization of fly ash and bottom ash in the construction of energy efficient buildings has been presented in this paper. Two masonry mortar grades MM3 and MM5 were considered for trial mix. Portland pozzolana cement with substitution of sand by fly ash and bottom ash separately in different substitution ratios (SR) were adopted for preparation of test samples. Fly ash and bottom ash with lime dust and marble dust combinations were also tested as sand free mortars. 28 days compressive strength, apparent porosity, bulk density and thermal conductivity parameters were evaluated for all such samples. By analysing the test results, it was observed that all the SR combinations satisfied the minimum masonry mortar grade MM0.7, as per IS 2250. Both the MM3 and MM5 grade mortars could be produced at 60% SR by fly ash, and corresponding reductions in thermal conductivity values were 69%, and 54% respectively, while compared with conventional mortar. Sand less mortar for both the grades resulted around 57% reductions in corresponding thermal conductivity values. Overall heat transfer co-efficient (U-value) for both side plastered and rendered brick masonry wall panel was found to be reduced by 15.58%, while comparison made between conventional mix of MM5 grade and corresponding 50% fly ash substituted mix. Thus such ash blended mortar mix appears to be advantageous in building envelop application for lowering the overall cooling/heating demand of building, besides utilizing the coal ash up to largest extent and saving natural mineral sand from depletion.

Systematic Multiscale Models to Predict the Compressive Strength of Cement Paste as a Function of Microsilica and Nanosilica Contents, Water/Cement Ratio, and Curing Ages

“…Environmental sustainability includes advanced innovations to monitor and minimize CO 2 emissions and energy usage and replace cement with supplementary cementitious materials, namely Pozzolans [1]. Diatomaceous earth [2], silica fume [3], volcanic ash [4], bottom ash, and husk/fly ash [5][6][7] are used in traditional pozzolans. Furthermore, several nanoparticles (NPs), for instance, carbon nanotubes [8], nano metakaolin [7,[9][10][11], nanosilica (NS) [7,[11][12][13][14][15][16], nano-Al 2 O 3 [17,18], nano-TiO 2 [19,20], nano-CuO [21], and nano-Fe 2 O 3 [22,23], have also recently been investigated with rapid improvements in nanomaterial technology.…”

A Review of Residential Buildings’ Sustainability Performance Using a Life Cycle Assessment Approach

“…Increased construction activity is exacerbating raw materials scarcity and emissions associated with the transportation and manufacturing of building materials [37]. Industrial by-products and waste materials like waste foundry sand [38,39], ground granulated blast furnace slag [40,41], steel slag [42,43], imperial smelting furnace slag [44], copper slag [45,46], bottom ash [47,48], class F type fly ash [48,49], silica fumes [50], palm oil clinker [51], rice husk ash [52,53], bagasse [54,55] and composites [56] have been found to improve buildings' structural and environmental performance when used instead of fine aggregates. Apart from generating industrial by-products, the recycling of C&D waste can also help reduce environmental impact and costs attributable to building materials [57]:…”

Mechanical Behaviour of Mortar Made with Washed Bottom Ash as Sand Replacement

“…Besides, the extreme weather such as increasing in heat frequency is the most important issue of energy required in the building. Reference [9] have mentioned that the energy efficiency in the building is not only minimised the electrical energy demand but also focussed on the performance of building especially operational energy and material used in building. Energy efficiency in the also discussed on natural ventilation, carbon dioxide (CO 2 ) emission and daylighting, and thermal insulation is very costly therefore choose the appropriate material is more significant [9].…”