Mechanical and physical properties of fly ash foamed concrete

• Main Author: M. Gelim, Khalid. Ali.
• Format: Thesis
• Language: English; English; English
• Published: 2011
• Subjects: TP Chemical technology; TP315-360 Fuel
• Online Access: http://eprints.uthm.edu.my/2665/1/24p%20KHALID.%20ALI.%20%20M.%20GELIM.pdf; http://eprints.uthm.edu.my/2665/2/KHALID.%20ALI.%20M.%20GELIM%20COPYRIGHT%20DECLARATION.pdf; http://eprints.uthm.edu.my/2665/3/KHALID.%20ALI.%20M.%20GELIM%20WATERMARK.pdf; http://eprints.uthm.edu.my/2665/

Foamed concrete has become most commercial material in construction industry. Fly ash is receiving more attention now since their uses generally improve the properties of blended cement concrete, cost saving and reduction of negative environmental affects. The physical and mechanical properties of foamed concrete differ according to a different type of mixture and its composition. Therefore, this research investigates physical and mechanical properties of fly ash foamed concrete. Fly ash was used as fine aggregate. Six series of fly ash foamed concrete for target densities (1000, 1100,1200,1300,1400 and 1500 kg/m ) with constant cement to fly ash ratio (1:1.5) and cement to water ratio (1:0.65) by weight were prepared and tested. Tests were conducted to study physical properties (work ability, water absorption, drying shrinkage and carbonation) and mechanical strengths properties (compressive, splitting tensile and flexural strengths). Three types of specimens (cube, cylinder and prism) were used in different quantity and different purposes. The specimens of drying shrinkage test were opened after one day but, others specimens were demoulded after three days and subjected to air curing under room temperature. As result, the findings from this project are very encouraging towards the use of fly ash foamed concrete density of 1100 and 1200 kg/m 3 in block application due to its compressive strength (3.7 – 6.7 MPa) whereas density of 1300, 1400 and 1500 kg/m 3 3 in structural application due to its high compressive strength (10 – 18.8 MPa) and moderate water absorption that was below 10%. It was also found that the physical properties of fly ash foamed concrete are high drying shrinkage between -666 to 1022 micro strain, high water absorption for density less than 1300 kg/m , higher workability (115 -180 mm diameter) and high carbonation depth that make it a good breathable material that removes carbon dioxide from our environment. Lastly comparative analyses were done to determine the relationships between the various mechanical properties parameters of the fly ash foamed concrete, namely the compressive strength, flexural strength, splitting tensile strength and mathematical equations were derived.