TY - JOUR
T1 - Influence of composition and concentration of alkaline activator on the properties of natural-pozzolan based green concrete
AU - Ibrahim, Mohammed
AU - Megat Johari, Megat Azmi
AU - Maslehuddin, Mohammed
AU - Rahman, Muhammed Kalimur
AU - Salami, Babatunde Abiodun
AU - Mohamed, Hatim Dafalla
N1 - Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2019/1/3
Y1 - 2019/1/3
N2 - The chemical constituents of precursor materials, the composition and concentration of alkaline activators, volume of free water, and curing conditions are some of the mix design variables that influence the fresh and hardened properties of alkali-activated binders (AABs). To achieve desirable engineering properties and long-term performance of an AAB under various exposure conditions, each of these variables has to be carefully controlled. The reported research focused on the influence of concentration and composition of alkaline activators on the properties of natural pozzolan (NP)-based AAB. Since the molarity of sodium hydroxide (SH) and the ratio of sodium silicate (SS) to sodium hydroxide (SH) influence the properties of an AAB, the NP-based AABs were prepared by varying the SS to SH ratio from 2.0 to 2.75, at an increment of 0.25, and the molarity of SH from 8 to 14. The developed AAC specimens were tested to evaluate the strength development and the binder was characterized using SEM, XRD and FTIR techniques. A SS/SH ratio of 2.5 and 14 M SH solution were required to obtain maximum strength and dense microstructure. In addition, it was established that there exists an optimum silica modulus of the combined activator that results in faster polymerization of the precursor material.
AB - The chemical constituents of precursor materials, the composition and concentration of alkaline activators, volume of free water, and curing conditions are some of the mix design variables that influence the fresh and hardened properties of alkali-activated binders (AABs). To achieve desirable engineering properties and long-term performance of an AAB under various exposure conditions, each of these variables has to be carefully controlled. The reported research focused on the influence of concentration and composition of alkaline activators on the properties of natural pozzolan (NP)-based AAB. Since the molarity of sodium hydroxide (SH) and the ratio of sodium silicate (SS) to sodium hydroxide (SH) influence the properties of an AAB, the NP-based AABs were prepared by varying the SS to SH ratio from 2.0 to 2.75, at an increment of 0.25, and the molarity of SH from 8 to 14. The developed AAC specimens were tested to evaluate the strength development and the binder was characterized using SEM, XRD and FTIR techniques. A SS/SH ratio of 2.5 and 14 M SH solution were required to obtain maximum strength and dense microstructure. In addition, it was established that there exists an optimum silica modulus of the combined activator that results in faster polymerization of the precursor material.
KW - Alkali-activated binder
KW - Mineralogical composition
KW - Molarity of sodium hydroxide
KW - Morphology
KW - Natural pozzolan
KW - Silica modulus
KW - Strength development
UR - http://www.scopus.com/inward/record.url?scp=85059327935&partnerID=8YFLogxK
U2 - 10.1016/j.conbuildmat.2018.12.117
DO - 10.1016/j.conbuildmat.2018.12.117
M3 - Article
AN - SCOPUS:85059327935
SN - 0950-0618
VL - 201
SP - 186
EP - 195
JO - Construction and Building Materials
JF - Construction and Building Materials
ER -