title: Fly ash-based geopolymer lightweight concrete using foaming agent.
abstract: In this paper, we report the results of our investigation on the possibility of producing foam concrete by using a geopolymer system. Class C fly ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH), and foam was added to the geopolymeric mixture to produce lightweight concrete. The NaOH solution was prepared by dilute NaOH pellets with distilled water. The reactives were mixed to produce a homogeneous mixture, which was placed into a 50 mm mold and cured at two different curing temperatures (60 °C and room temperature), for 24 hours. After the curing process, the strengths of the samples were tested on days 1, 7, and 28. The water absorption, porosity, chemical composition, microstructure, XRD and FTIR analyses were studied. The results showed that the sample which was cured at 60 °C (LW2) produced the maximum compressive strength for all tests, (11.03 MPa, 17.59 MPa, and 18.19 MPa) for days 1, 7, and 28, respectively. Also, the water absorption and porosity of LW2 were reduced by 6.78% and 1.22% after 28 days, respectively. The SEM showed that the LW2 sample had a denser matrix than LW1. This was because LW2 was heat cured, which caused the geopolymerization rate to increase, producing a denser matrix. However for LW1, microcracks were present on the surface, which reduced the compressive strength and increased water absorption and porosity.
authors: Center of Excellence Geopolymer and Green Technology, School of Materials Engineering, Universiti Malaysia Perlis (UniMAP), P.O. Box 77, D/A Pejabat Pos Besar, Kangar Perlis 01000, Malaysia.
authors: Mohd Mustafa Al Bakri
authors: MMAB
authors: Abdullah
authors: Center of Excellence Geopolymer and Green Technology, School of Materials Engineering, Universiti Malaysia Perlis (UniMAP), P.O. Box 77, D/A Pejabat Pos Besar, Kangar Perlis 01000, Malaysia.
authors: Kamarudin
authors: K
authors: Hussin
authors: King Abdul Aziz Science & Technology (KACST), P.O. Box 6086, Riyadh 11442, Kingdom of Saudi Arabia.
authors: Mohamed
authors: M
authors: Bnhussain
authors: School of Environmental Engineering, Universiti Malaysia Perlis (UniMAP), P.O. Box 77, D/A Pejabat Pos Besar, Kangar, Perlis 01000, Malaysia.
authors: Khairul Nizar
authors: KN
authors: Ismail
authors: Center of Excellence Geopolymer and Green Technology, School of Materials Engineering, Universiti Malaysia Perlis (UniMAP), P.O. Box 77, D/A Pejabat Pos Besar, Kangar Perlis 01000, Malaysia.
authors: Zarina
authors: Z
authors: Yahya
authors: Center of Excellence Geopolymer and Green Technology, School of Materials Engineering, Universiti Malaysia Perlis (UniMAP), P.O. Box 77, D/A Pejabat Pos Besar, Kangar Perlis 01000, Malaysia.
authors: Rafiza
authors: R
authors: Abdul Razak
mesh_terms: D003252:Construction Materials; D017640:Silicates / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry*
chemical_list: D017640:Silicates; D012972:Sodium Hydroxide; C005691:sodium silicate