Use of Water Glass from Rice Husk and Bagasse Ashes in the Preparation of Fly Ash Based Geopolymer

2019 ◽  
Vol 798 ◽  
pp. 364-369 ◽  
Author(s):  
Khemmakorn Gomonsirisuk ◽  
Parjaree Thavorniti

The aim of this work is to study the feasibility of preparation of fly ash based geopolymer using sodium water glass from agricultural waste as alternative activators. Rice husk ash and bagasse ash were used as raw materials for producing sodium water glass solution. The sodium water glass were produced by mixing rice husk ash and bagasse ash with NaOH in ball mill and boiling. The prepared sodium water glass were analyzed and used in geopolymer preparation process. The geopolymer paste were prepared by adding the obtained water glass and NaOH with fly ash. After cured at ambient temperature for 7 days, mechanical properties were investigated. Bonding and phases of the geopolymer were also characterized. The geopolymer from rice husk ash presented highest compressive strength about 23 MPa while the greatest for bagasse ash was about 16 MPa.

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 197
Author(s):  
Jozef Vlček ◽  
Michaela Topinková ◽  
Miroslava Klárová ◽  
Petra Maierová ◽  
Hana Ovčačíková ◽  
...  

Metakaolin (MK) prepared by the calcination of kaolin at 550 °C and fly ash (FA) from the combustion of black coal in a granulating boiler were used to prepare unfired ceramic bonding systems via the alkali activation process. A long-term stability of the mechanical properties of the prepared samples similar to the unfired ceramic systems was observed. The optimal metakaolin and fly ash ratio, the type of the activator (NaOH or water glass) and its concentration were evaluated after the hydration in: a) laboratory conditions; b) hydration box; and c) under the hydrothermal activation. Raw materials and the samples prepared by alkali activation process were characterized by XRD, XRF, TG/DTA, and FTIR methods. The mechanical properties of the prepared samples were tested using a compressive strength test after 2, 28 and 56 days of hydration. The compressive strengths of 16 and 24 MPa after 28 days of hydration were reached for FA samples activated with water glass. The alkali activation of MK was successful in the NaOH solution of the molar concentration above 5 M. The compressive strength values of metakaolin, activated hydrothermally and hydrated at laboratory conditions, reached 11.2 and 5.5 MPa, respectively, for 5 M activator of NaOH.


2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Mohamed Amin ◽  
Bassam Abdelsalam Abdelsalam

AbstractMany environmental problems occur due to rice husk burning and emissions from coal-fired power stations. This paper presents the recycling of rice husk ash (RHA) and fly ash (FA) from power plants as reactivity materials for producing sustainable (green) concrete. This research aims to investigate the efficiency of RHA and FA replacement ratios on fresh and hardened properties of concrete mixtures. The experimental program consisted of 21 concrete mixtures, which were divided into three groups. The cementitious material contents were 350, 450 and 550 kg m−3 for groups one, two and three, respectively. The replacement ratios from the cement content were 10, 20 and 30% respectively, for each recycle material (RHA and FA). The slump and air contents of fresh concrete were measured. The compressive strength, splitting tensile strength, flexural strength, modulus of elasticity and bond strength of hardened concrete as mechanical properties were also analyzed. The compressive strength was monitored at different ages: 3, 7, 28, 60 and 90 d. The water permeability test of hardened concrete as physical properties was conducted. Test results showed that the RHA and FA enhanced the mechanical and physical properties compared with the control mixture. The cementitious content of 450 kg m−3 exhibited better results than other utilized contents. In particular, the replacement ratios of 10 and 30% of RHA presented higher mechanical properties than those of FA for each group. The water permeability decreased as the cementitious content increased due to the decrease in air content for all mixtures. The water permeability loss ratios increased as the cementitious content decreased.


Chapter 3 is based on performance of mortar grouts incorporating rice husk ash (RHA) and fly ash (FA). Detailed experimental work was conducted to investigate the mechanical properties of mortar grout using RHA and FA as partial replacement of cement. This study investigated the compressive strength and durability of mortar grouts in their hardened state. Durability tests such as water absorption, apparent volume of permeable voids, sorptivity, and rapid chloride penetration tests are researched. Detailed results and discussion which focused on mechanical properties as well as durability of hardened state mortar grout are presented. It was confirmed that the inclusion of blended RHA and FA significantly improved the compressive strength of mortar grouts. The durability of mortar grout increased along with a longer curing time. Hence, RHA and FA can partially replace cement in the production of mortar grouts.


2015 ◽  
Vol 804 ◽  
pp. 129-132
Author(s):  
Sumrerng Rukzon ◽  
Prinya Chindaprasirt

This research studies the potential for using waste ash from industrial and agricultural by-products as a pozzolanic material. Classified fly ash (FA) and ground rice husk ash (RA) were the materials used. Water requirement, compressive strength and porosity of cement mortar were investigated. Test results indicated that FA and RA (waste ash) have a high potential to be used as a good pozzolanic material. The water requirement of mortar mix decreases with the increases in fly ash content. For ground rice husk ash (RA), the water requirement of mortar mix increases with the increases in rice husk ash content. In addition, the reduction in porosity was associated with the increase in compressive strength.


2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
M. R. Karim ◽  
M. F. M. Zain ◽  
M. Jamil ◽  
F. C. Lai

The increasing demand and consumption of cement have necessitated the use of slag, fly ash, rice husk ash (RHA), and so forth as a supplement of cement in concrete construction. The aim of the study is to develop a zero-cement binder (Z-Cem) using slag, fly ash, and RHA combined with chemical activator. NaOH, Ca(OH)2, and KOH were used in varying weights and molar concentrations. Z-Cem was tested for its consistency, setting time, flow, compressive strength, XRD, SEM, and FTIR. The consistency and setting time of the Z-Cem paste increase with increasing RHA content. The Z-Cem mortar requires more superplasticizer to maintain a constant flow of110±5% compared with OPC. The compressive strength of the Z-Cem mortar is significantly influenced by the amounts, types, and molar concentration of the activators. The Z-Cem mortar achieves a compressive strength of 42–44 MPa at 28 days with 5% NaOH or at 2.5 molar concentrations. The FTIR results reveal that molecules in the Z-Cem mortar have a silica-hydrate (Si-H) bond with sodium or other inorganic metals (i.e., sodium/calcium-silica-hydrate-alumina gel). Therefore, Z-Cem could be developed using the aforementioned materials with the chemical activator.


2018 ◽  
Vol 766 ◽  
pp. 305-310 ◽  
Author(s):  
Chayanee Tippayasam ◽  
Sarochapat Sutikulsombat ◽  
Jamjuree Paramee ◽  
Cristina Leonelli ◽  
Duangrudee Chaysuwan

Geopolymer is a greener alternative cement produced from the reaction of pozzolans and strong alkali solutions. Generally, the cement industry is one of largest producers of CO2that caused global warming. For geopolymer mortar usage, Portland cement is not utilized at all. In this research, geopolymer mortars were prepared by mixing metakaolin, various wastes (fly ash, bagasse ash and rice husk ash) varied as 80:20, 50:50 and 20:80, 15M NaOH, Na2SiO3and sand. The influence of various parameters such as metakaolin to ashes ratios and pozzolans to alkali ratios on engineering properties of metakaolin blended wastes geopolymer mortar were studied. Compressive strength tests were carried out on 25 x 25 x 25 mm3cube geopolymer mortar specimens at 7, 14, 21, 28 and 91 air curing days. Physical and chemical properties were also investigated at the same times. The test results revealed that the highest compressive strength was 20% metakaolin - 80% fly ash geopolymer mortar. When the curing times increases, the compressive strength of geopolymer mortar also increases. The mixing of metakaolin and bagasse ash/rice husk ash presented lower compressive strength but higher water absorption and porosity. For FTIR results, Si-O, Al-O and Si-O-Na+were found. Moreover, the geopolymer mortar could easily plastered on the wall.


2015 ◽  
Vol 754-755 ◽  
pp. 468-472 ◽  
Author(s):  
Chao Lung Hwang ◽  
Trong Phuoc Huynh

This work investigates the possibility of using fly ash (FA) and Vietnam residual rice husk ash (RHA) in producing unfired building bricks with applying densified mixture design algorithm (DMDA) method. In this research, little amount of cement was added into the mixtures as binder substitution. Unground rice husk ash (URHA), an agricultural by-product, was used as partial fine aggregate replacement (10% and 30%) in the mixtures. The solid bricks of 220×105×60 mm in size were prepared in this study. The hardened properties of the bricks were investigated including compressive strength, flexural strength and water absorption according to corresponding Vietnamese standards. Forming pressure of 35 MPa was applied to form the solid bricks in the mold. The test results show that all brick specimens obtained good mechanical properties, which were well conformed to Vietnamese standard. Compressive strength and flexural strength of the bricks were respectively in range of 13.81–22.06 MPa and 2.25–3.47 MPa. It was definitely proved many potential applications of FA and RHA in the production of unfired building bricks.


2020 ◽  
Vol 13 (3) ◽  
pp. 315-321
Author(s):  
Dhiraj Ahiwale ◽  
Rushikesh Khartode

Now days, the waste rice husk from rice mill, marble powder from tile industry and fly ash from steam power plant are necessary to utilize as partial replacement of cement for concrete production. Large scale production of cement required consumption of raw materials and energy as well as emissions to air which posse’s environmental threat in various areas of country. Apart from the environmental threat, there still exists the problem of shortage in many areas. Therefore, substitute material for concrete needs to be considered. The paper aims to analyze the compressive strength of concrete cubes and flexural strength of concrete beams made from partially replaced cement, sand, and coarse aggregate. This research study adopted in laboratory on 48 total specimens of grade M25 concrete cubes of size 150x150x150mm and concrte beams of size 100x100x500mm were casted. Out of the 48 concrete specimens cast, 6 each were made out 10%, 20%, and 30 % replacement of fly ash, rice husk ash and marble powder to cement in concrete. It was found that the compressive strength and flexural strength of concrete made from the mixture of 20 % partially replaced cement, sand and coarse aggregate was similar than the concrete made from without replaced cement , sand and coarse aggregate.


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