Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

• Published in: International journal of molecular sciences 2015-05, Vol.16 (5), p.11629-11647
• Main Authors: Razak, Rafiza Abdul, Abdullah, Mohd Mustafa Al Bakri, Hussin, Kamarudin, Ismail, Khairul Nizar, Hardjito, Djwantoro, Yahya, Zarina
• Format: Article
• Language: English
• Subjects: aggregate impact value; artificial lightweight aggregate; Crystallization; Fourier Transform Infrared (FTIR); geopolymer; Gravity; Polymers; Polymers - chemistry; SEM; Silicates - chemistry; Sodium Hydroxide - chemistry; Spectroscopy, Fourier Transform Infrared; Water - chemistry; X-Ray Diffraction; X-ray Diffraction (XRD); X-rays
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms160511629

This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced.