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Suksun Horpibulsuk - One of the best experts on this subject based on the ideXlab platform.
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marginal lateritic soil stabilized with Calcium Carbide residue and fly ash geopolymers as a sustainable pavement base material
Journal of Materials in Civil Engineering, 2017Co-Authors: Itthikorn Phummiphan, Tanakorn Phoongernkham, Suksun Horpibulsuk, Arul Arulrajah, Shuilong ShenAbstract:AbstractTwo waste by-products, fly ash (FA) and Calcium Carbide residue (CCR), are used to develop geopolymer binders for stabilizing marginal lateritic soil as a sustainable pavement base. The liquid alkaline activator is a mixture of sodium silicate solution (Na2SiO3) and sodium hydroxide (NaOH) at a concentration of 10 molars. Unconfined compressive strength (UCS) and scanning electron microscopy (SEM) images of lateritic soil–FA geopolymers at different influential factors (curing times, Na2SiO3∶NaOH ratios, and CCR replacement ratios) are measured. The soaked 7-day UCS of lateritic soil–FA geopolymers meets the strength requirement for both light and heavy traffic pavement specified by the local national authorities. The early 7-day UCS and cementitious products increase with increasing CCR replacement ratio, and the cementitious products are clearly observed at CCR = 30% (the highest CCR replacement ratio tested). However, the CCR replacement ratio providing the maximum 90-day strength is found at 2...
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strength development in soft marine clay stabilized by fly ash and Calcium Carbide residue based geopolymer
Applied Clay Science, 2016Co-Authors: Chayakrit Phetchuay, Cherdsak Suksiripattanapong, Suksun Horpibulsuk, Arul Arulrajah, Artit UdomchaiAbstract:This research investigates strength development and the carbon footprint of Calcium Carbide Residue (CCR) and Fly Ash (FA) based geopolymer stabilized marine clay. Coode Island Silt (CIS), a soft and highly compressible marine clay present in Melbourne, Australia was investigated for stabilization with the CCR and FA geopolymers. CCR is an industrial by-product obtained from acetylene gas production, high in Ca(OH)2 and was used as a green additive to improve strength of the FA based geopolymer binder. The liquid alkaline activator used was a mixture of sodium silicate solution (Na2SiO3) and sodium hydroxide (NaOH). The influential factors studied for the geopolymerization process were Na2SiO3/NaOH ratio, NaOH concentration, L/FA ratio, initial water content, FA content, CCR content, curing temperature and curing time. The strength of stabilized CIS was found to be strongly dependent upon FA content and NaOH concentration. The optimal ingredient providing the highest strength was found to be dependent on water content. Higher water contents were found to dilute the NaOH concentration, hence the optimal L/FA increases and the optimal Na2SiO3/NaOH decreases as the water content present in the clay increases. The maximum strength of the FA geopolymer (without CCR) stabilized CIS was found at Na2SiO3/NaOH = 70:30 ratio and L/FA = 1.0 for clay water content at liquid limit (LL). The role of CCR on the strength of FA geopolymer stabilized CIS can be classified into three zones: inactive, active and quasi-inert. The active zone where CCR content is between 7% and 12% is recommended in practice. The 12% CCR addition can improve up to 1.5 times the strength of the FA geopolymer. The carbon footprints of the geopolymer stabilized soils were approximately 22%, 23% and 43% lower than those of cement stabilized soil at the same strengths of 400 kPa, 600 kPa and 800 kPa. The reduction in carbon footprints at high strength indicates the effectiveness of FA geopolymer as an alternative and effective green soil stabilizer to traditional Portland cement.
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stabilization of recycled demolition aggregates by geopolymers comprising Calcium Carbide residue fly ash and slag precursors
Construction and Building Materials, 2016Co-Authors: Arul Arulrajah, Suksun Horpibulsuk, Alireza Mohammadinia, Itthikorn Phummiphan, Wisanukorn SamingthongAbstract:Abstract Calcium Carbide Residue (CCR) is the by-product of acetylene gas production. In this research, the alkali activation of Calcium Carbide Residue (CCR) was studied as an economical and low-carbon precursor for development of geopolymer binder. Recycled Concrete aggregates (RCA) and Crushed Brick (CB) are the two major demolition material sources for the Construction and Demolition (C&D) industry. The cement stabilization of C&D materials has been evaluated in recent years, however due to the large carbon footprint associated with Portland cement, geopolymers which utilize the alkali activation of industrial waste by-products have garnered increasing interest from industry. Evaluation of the geopolymer stabilization of C&D materials with CCR precursor were also compared with traditional Fly Ash (FA) and Slag (S) precursors. In addition, the performance of CCR based geopolymers with supplementary FA and S precursors were also evaluated. The three precursors (CCR, FA, S) were combined with contents of up to 10% for the geopolymer stabilization of the C&D materials. A liquid alkaline activator comprising sodium silicate solution (Na 2 SiO 3 ) and sodium hydroxide (NaOH) was used for the alkali activation of the CCR based geopolymers. The strength and durability of the geopolymer stabilized C&D materials were evaluated to ascertain their application in pavement bases/subbases. The results of Unconfined Compressive Strength (UCS) and Resilient Modulus (M R ) testing of these geopolymer stabilized CB and RCA aggregates indicate that different mixtures of CCR based geopolymers can be used to improve the strength properties of the C&D aggregates for pavement base/subbase applications. CCR + 5% S with the C&D materials resulted in the optimum combination for CCR based geopolymer stabilization of C&D aggregates.
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field evaluation of soft highway subgrade soil stabilized with Calcium Carbide residue
Soils and Foundations, 2016Co-Authors: Yanjun Du, Suksun Horpibulsuk, Ningjun Jiang, Arul ArulrajahAbstract:Abstract Calcium Carbide residue (CCR) is a by-product of acetylene gas production. Stockpiles of CCR continue to accumulate worldwide, in both developed and developing countries. Sustainable reuse options for CCR in civil infrastructures, such as road embankments, have been recently evaluated in the laboratory. However, to date there are limited studies on the actual field performance of CCR in stabilizing clayey soils in highway subgrades. In this study, a field trial was conducted to ascertain the viability of using CCR stabilized clayey soil as a highway subgrade course material. Quicklime was selected as a control binder in the field trial for comparison purposes. The construction procedures of the CCR and quicklime stabilizations in two field sections are presented. A series of field tests, including California Bearing Ratio (CBR) test, plate loading test, Benkelman beam deflection test, and dynamic cone penetrometer (DCP) test were undertaken after the embankment construction. The results indicated that in the top zone of the filled soil layers with 94% degree of compaction, the CCR stabilized subgrade soil exhibited higher values of CBR and resilient modulus, and lower values of resilient deflection and DCP Index relative to the quicklime stabilized soil. The field trial results indicated that CCR had negligible environmental effects and furthermore resulted in low construction costs. Based on the field test results, CCR was found to be a viable alternative binder for stabilizing soft subgrade soils. The outcomes of this research are significant from engineering, economic and environmental perspectives.
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multi scale laboratory evaluation of the physical mechanical and microstructural properties of soft highway subgrade soil stabilized with Calcium Carbide residue
Canadian Geotechnical Journal, 2016Co-Authors: Suksun Horpibulsuk, Yanjun Du, Ningjun Jiang, Arul ArulrajahAbstract:Calcium Carbide residue (CCR) is an industrial by-product, stockpiles of which are rapidly accumulating worldwide. Highway embankment construction has been identified as an avenue to consume huge quantities of CCR as an economical, less energy intensive, and environmentally friendly chemical additive for soil stabilization. Previous studies have investigated the mechanical behavior of soils stabilized by CCR or blends of CCR with other additives; however, interpretation of the macroscale geomechanical behavior of CCR-stabilized soft soils from a systematically microstructural observation and analysis is relatively unknown. This paper presents a multi-scale laboratory investigation on the physical, mechanical, and microstructural properties of CCR-stabilized clayey soils with comparison to quicklime-stabilized soils. Several series of tests were conducted to examine the Atterberg limits, particle-size distribution, compaction characteristics, unconfined compressive strength, California Bearing Ratio, and r...
Arul Arulrajah - One of the best experts on this subject based on the ideXlab platform.
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marginal lateritic soil stabilized with Calcium Carbide residue and fly ash geopolymers as a sustainable pavement base material
Journal of Materials in Civil Engineering, 2017Co-Authors: Itthikorn Phummiphan, Tanakorn Phoongernkham, Suksun Horpibulsuk, Arul Arulrajah, Shuilong ShenAbstract:AbstractTwo waste by-products, fly ash (FA) and Calcium Carbide residue (CCR), are used to develop geopolymer binders for stabilizing marginal lateritic soil as a sustainable pavement base. The liquid alkaline activator is a mixture of sodium silicate solution (Na2SiO3) and sodium hydroxide (NaOH) at a concentration of 10 molars. Unconfined compressive strength (UCS) and scanning electron microscopy (SEM) images of lateritic soil–FA geopolymers at different influential factors (curing times, Na2SiO3∶NaOH ratios, and CCR replacement ratios) are measured. The soaked 7-day UCS of lateritic soil–FA geopolymers meets the strength requirement for both light and heavy traffic pavement specified by the local national authorities. The early 7-day UCS and cementitious products increase with increasing CCR replacement ratio, and the cementitious products are clearly observed at CCR = 30% (the highest CCR replacement ratio tested). However, the CCR replacement ratio providing the maximum 90-day strength is found at 2...
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strength development in soft marine clay stabilized by fly ash and Calcium Carbide residue based geopolymer
Applied Clay Science, 2016Co-Authors: Chayakrit Phetchuay, Cherdsak Suksiripattanapong, Suksun Horpibulsuk, Arul Arulrajah, Artit UdomchaiAbstract:This research investigates strength development and the carbon footprint of Calcium Carbide Residue (CCR) and Fly Ash (FA) based geopolymer stabilized marine clay. Coode Island Silt (CIS), a soft and highly compressible marine clay present in Melbourne, Australia was investigated for stabilization with the CCR and FA geopolymers. CCR is an industrial by-product obtained from acetylene gas production, high in Ca(OH)2 and was used as a green additive to improve strength of the FA based geopolymer binder. The liquid alkaline activator used was a mixture of sodium silicate solution (Na2SiO3) and sodium hydroxide (NaOH). The influential factors studied for the geopolymerization process were Na2SiO3/NaOH ratio, NaOH concentration, L/FA ratio, initial water content, FA content, CCR content, curing temperature and curing time. The strength of stabilized CIS was found to be strongly dependent upon FA content and NaOH concentration. The optimal ingredient providing the highest strength was found to be dependent on water content. Higher water contents were found to dilute the NaOH concentration, hence the optimal L/FA increases and the optimal Na2SiO3/NaOH decreases as the water content present in the clay increases. The maximum strength of the FA geopolymer (without CCR) stabilized CIS was found at Na2SiO3/NaOH = 70:30 ratio and L/FA = 1.0 for clay water content at liquid limit (LL). The role of CCR on the strength of FA geopolymer stabilized CIS can be classified into three zones: inactive, active and quasi-inert. The active zone where CCR content is between 7% and 12% is recommended in practice. The 12% CCR addition can improve up to 1.5 times the strength of the FA geopolymer. The carbon footprints of the geopolymer stabilized soils were approximately 22%, 23% and 43% lower than those of cement stabilized soil at the same strengths of 400 kPa, 600 kPa and 800 kPa. The reduction in carbon footprints at high strength indicates the effectiveness of FA geopolymer as an alternative and effective green soil stabilizer to traditional Portland cement.
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stabilization of recycled demolition aggregates by geopolymers comprising Calcium Carbide residue fly ash and slag precursors
Construction and Building Materials, 2016Co-Authors: Arul Arulrajah, Suksun Horpibulsuk, Alireza Mohammadinia, Itthikorn Phummiphan, Wisanukorn SamingthongAbstract:Abstract Calcium Carbide Residue (CCR) is the by-product of acetylene gas production. In this research, the alkali activation of Calcium Carbide Residue (CCR) was studied as an economical and low-carbon precursor for development of geopolymer binder. Recycled Concrete aggregates (RCA) and Crushed Brick (CB) are the two major demolition material sources for the Construction and Demolition (C&D) industry. The cement stabilization of C&D materials has been evaluated in recent years, however due to the large carbon footprint associated with Portland cement, geopolymers which utilize the alkali activation of industrial waste by-products have garnered increasing interest from industry. Evaluation of the geopolymer stabilization of C&D materials with CCR precursor were also compared with traditional Fly Ash (FA) and Slag (S) precursors. In addition, the performance of CCR based geopolymers with supplementary FA and S precursors were also evaluated. The three precursors (CCR, FA, S) were combined with contents of up to 10% for the geopolymer stabilization of the C&D materials. A liquid alkaline activator comprising sodium silicate solution (Na 2 SiO 3 ) and sodium hydroxide (NaOH) was used for the alkali activation of the CCR based geopolymers. The strength and durability of the geopolymer stabilized C&D materials were evaluated to ascertain their application in pavement bases/subbases. The results of Unconfined Compressive Strength (UCS) and Resilient Modulus (M R ) testing of these geopolymer stabilized CB and RCA aggregates indicate that different mixtures of CCR based geopolymers can be used to improve the strength properties of the C&D aggregates for pavement base/subbase applications. CCR + 5% S with the C&D materials resulted in the optimum combination for CCR based geopolymer stabilization of C&D aggregates.
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field evaluation of soft highway subgrade soil stabilized with Calcium Carbide residue
Soils and Foundations, 2016Co-Authors: Yanjun Du, Suksun Horpibulsuk, Ningjun Jiang, Arul ArulrajahAbstract:Abstract Calcium Carbide residue (CCR) is a by-product of acetylene gas production. Stockpiles of CCR continue to accumulate worldwide, in both developed and developing countries. Sustainable reuse options for CCR in civil infrastructures, such as road embankments, have been recently evaluated in the laboratory. However, to date there are limited studies on the actual field performance of CCR in stabilizing clayey soils in highway subgrades. In this study, a field trial was conducted to ascertain the viability of using CCR stabilized clayey soil as a highway subgrade course material. Quicklime was selected as a control binder in the field trial for comparison purposes. The construction procedures of the CCR and quicklime stabilizations in two field sections are presented. A series of field tests, including California Bearing Ratio (CBR) test, plate loading test, Benkelman beam deflection test, and dynamic cone penetrometer (DCP) test were undertaken after the embankment construction. The results indicated that in the top zone of the filled soil layers with 94% degree of compaction, the CCR stabilized subgrade soil exhibited higher values of CBR and resilient modulus, and lower values of resilient deflection and DCP Index relative to the quicklime stabilized soil. The field trial results indicated that CCR had negligible environmental effects and furthermore resulted in low construction costs. Based on the field test results, CCR was found to be a viable alternative binder for stabilizing soft subgrade soils. The outcomes of this research are significant from engineering, economic and environmental perspectives.
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multi scale laboratory evaluation of the physical mechanical and microstructural properties of soft highway subgrade soil stabilized with Calcium Carbide residue
Canadian Geotechnical Journal, 2016Co-Authors: Suksun Horpibulsuk, Yanjun Du, Ningjun Jiang, Arul ArulrajahAbstract:Calcium Carbide residue (CCR) is an industrial by-product, stockpiles of which are rapidly accumulating worldwide. Highway embankment construction has been identified as an avenue to consume huge quantities of CCR as an economical, less energy intensive, and environmentally friendly chemical additive for soil stabilization. Previous studies have investigated the mechanical behavior of soils stabilized by CCR or blends of CCR with other additives; however, interpretation of the macroscale geomechanical behavior of CCR-stabilized soft soils from a systematically microstructural observation and analysis is relatively unknown. This paper presents a multi-scale laboratory investigation on the physical, mechanical, and microstructural properties of CCR-stabilized clayey soils with comparison to quicklime-stabilized soils. Several series of tests were conducted to examine the Atterberg limits, particle-size distribution, compaction characteristics, unconfined compressive strength, California Bearing Ratio, and r...
Valentine P Ananikov - One of the best experts on this subject based on the ideXlab platform.
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examining the vinyl moiety as a protecting group for hydroxyl oh functionality under basic conditions
Organic chemistry frontiers, 2020Co-Authors: V V Voronin, Konstantin S Rodygin, Maria S Ledovskaya, Valentine P AnanikovAbstract:A method for protection of alcohols with vinyl groups is suggested and studied in detail. The procedures of protection and deprotection via vinylation and devinylation reactions are evaluated. Vinylation reaction is performed using cheap and convenient Calcium Carbide reagent. Stability of the vinyl group under various conditions is examined. The vinyl group is found to be stable under basic conditions and labile under acidic conditions. The vinyl protecting group shows high tolerance to functional groups and good compatibility with common synthetic reagents. Applicability of the procedure in the Suzuki and Sonogashira catalytic reactions and its flexible utilization in the reaction with Grignard reagent are demonstrated.
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Calcium Carbide a unique reagent for organic synthesis and nanotechnology
ChemInform, 2016Co-Authors: Konstantin S Rodygin, Georg Werner, Fedor A Kucherov, Valentine P AnanikovAbstract:Acetylene, HC≡CH, is one of the primary building blocks in synthetic organic and industrial chemistry. Several highly valuable processes have been developed based on this simplest alkyne and the development of acetylene chemistry has had a paramount impact on chemical science over the last few decades. However, in spite of numerous useful possible reactions, the application of gaseous acetylene in everyday research practice is rather limited. Moreover, the practical implementation of high-pressure acetylene chemistry can be very challenging, owing to the risk of explosion and the requirement for complex equipment; special safety precautions need to be taken to store and handle acetylene under high pressure, which limit its routine use in a standard laboratory setup. Amazingly, recent studies have revealed that Calcium Carbide, CaC2 , can be used as an easy-to-handle and efficient source of acetylene for in situ chemical transformations. Thus, Calcium Carbide is a stable and inexpensive acetylene precursor that is available on the ton scale and it can be handled with standard laboratory equipment. The application of Calcium Carbide in organic synthesis will bring a new dimension to the powerful acetylene chemistry.
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Calcium Carbide as a convenient acetylene source in the synthesis of unsaturated sulfides promising functionalized monomers
ChemInform, 2016Co-Authors: Konstantin S Rodygin, Anton A Kostin, Valentine P AnanikovAbstract:Calcium Carbide was studied as a useful solid-state reagent to incorporate acetylene unit into synthetic procedures. Atom-economic thiol-yne click reaction was successfully performed with single and double additions. Heterocyclic thiols and aliphatic dithiols reacted with acetylene generated in situ from Calcium Carbide to afford corresponding vinyl sulfides and bis(thiovinyl)ethers in good to high yields.
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an efficient metal free pathway to vinyl thioesters with Calcium Carbide as the acetylene source
Green Chemistry, 2016Co-Authors: Konstantin S Rodygin, Valentine P AnanikovAbstract:Chemical reactions involving high-pressure acetylene are not easily performed in a standard laboratory setup. The risk of explosion and technical difficulties drastically complicate the equipment and greatly increase the cost. In this study, we propose the replacement of acetylene with Calcium Carbide, which was successfully utilized to synthesize practically useful vinyl thioesters in accordance with a simple and environmentally benign procedure. The reaction proceeded under mild conditions using a standard laboratory setup. The optimized reaction conditions allowed the selective synthesis of the vinyl thioesters in high yields, and the reaction conditions can be scaled up to synthesize grams of sulfides from inexpensive starting materials.
Chai Jaturapitakkul - One of the best experts on this subject based on the ideXlab platform.
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autogenous and drying shrinkages of mortars and pore structure of pastes made with activated binder of Calcium Carbide residue and fly ash
Construction and Building Materials, 2020Co-Authors: Saofee Dueramae, Prinya Chindaprasirt, Weerachart Tangchirapat, Chai Jaturapitakkul, Piti SukontasukkulAbstract:Abstract Present study evaluates the strength development and shrinkage characteristics of mortars made with a non-cement binder composed of Calcium Carbide residue and fly ash under several activation techniques. The activation techniques used for improving the strength development were adding NaOH to the binder (0.5, 1.0, and 1.5% by weight of binder), curing at a temperature of 60 °C, and combining both adding NaOH and curing at a temperature of 60 °C. The compressive strengths of mortars were examined at 3, 7, 28 and 90 days. The shrinkage characteristics of the mortars were evaluated in terms of the autogenous and drying shrinkages. The pore structure of the paste was also analyzed using mercury intrusion porosimetry. The results showed that all of the activation techniques could enhance the compressive strength of mortar and improve the pore structure of the paste made from the mixture of Calcium Carbide residue and fly ash. The technique to improve strength by combining addition of NaOH and curing at 60 °C was found to be the most effective method, and produced the mortar with a compressive strength as high as 51.1 MPa at 90 days. The shrinkage behaviors of the mortar made from the mixture of Calcium Carbide residue and fly ash were similar to the ordinary Portland cement mortar. The autogenous shrinkage was associated with the internal reaction process, while the drying shrinkage was depended on evaporation of water in pore structures during the drying process. Additionally, the use of NaOH as an activator significantly increased the magnitude of the autogenous and drying shrinkages of mortar. However, the drying shrinkage was greatly reduced with the activation by curing at 60 °C.
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use of Calcium Carbide residue and bagasse ash mixtures as a new cementitious material in concrete
Materials & Design, 2013Co-Authors: Chaiyanunt Rattanashotinunt, Weerachart Tangchirapat, Pongsiri Thairit, Chai JaturapitakkulAbstract:Abstract Calcium Carbide residue (CCR) is a by-product of the acetylene gas production and bagasse ash (BA) is a by-product obtained from the burning of bagasse for electricity generation in the sugar industry. The mixture between CCR contains a high proportion of Calcium hydroxide, while BA is a pozzolanic material, can produce a pozzolanic reaction, resulting in the products similar to those obtained from the cement hydration process. Thus, it is possible to use a mixture of CCR and BA as a cementitious material to substitute for Portland cement in concrete. The results indicated that concrete made with CCR and BA mixtures and containing 90 kg/m3 of Portland cement gave the compressive strength of 32.7 MPa at 28 days. These results suggested that the use of ground CCR and ground BA mixtures as a binder could reduce Portland cement consumption by up to 70% compared to conventional concrete that requires 300 kg/m3 of Portland cement to achieve the same compressive strength. In addition, the mechanical properties of the alternative concrete including compressive strength, splitting tensile strength, and elastic modulus were similar to that of conventional concrete.
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effects of Calcium Carbide residue fly ash binder on mechanical properties of concrete
Journal of Materials in Civil Engineering, 2010Co-Authors: Nattapong Makaratat, Chai Jaturapitakkul, Thanapol LaosamathikulAbstract:This study investigated the use of two kinds of waste from landfills, Calcium Carbide residue and fly ash, as a low CO2 emission concrete binder. Calcium Carbide residue is a by-product of an acetylene gas production process, and fly ash is a by-product of a thermal power plant. Ground Calcium Carbide residue (CR) was mixed with original fly ash (OF) or ground fly ash (GF) at a ratio of 30:70 by weight and was used as a binder to cast concrete without portland cement. The effects of fly ash finenesses and water to binder ( W/B ) ratios of CR-OF and CR-GF concretes on setting times, compressive strength, modulus of elasticity, and splitting tensile strength were investigated. The results indicated that CR-OF and CR-GF mixtures could not only be used as a new binder in concrete but could also help reduce environmental problems associated with CO2 emissions. Without the use of portland cement, CR-GF concrete yielded compressive strengths of 28.4 and 33.5 MPa at 28 and 90 days, respectively. In addition, lowe...
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cementing material from Calcium Carbide residue rice husk ash
Journal of Materials in Civil Engineering, 2003Co-Authors: Chai Jaturapitakkul, Boonmark RoongreungAbstract:This paper proposes a new cementitious material from a mixture of Calcium Carbide residue and rice husk ash. Calcium Carbide residue and rice husk ash consist mainly of Ca(OH)2 and SiO2, respective...
Chayakrit Phetchuay - One of the best experts on this subject based on the ideXlab platform.
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strength development in soft marine clay stabilized by fly ash and Calcium Carbide residue based geopolymer
Applied Clay Science, 2016Co-Authors: Chayakrit Phetchuay, Cherdsak Suksiripattanapong, Suksun Horpibulsuk, Arul Arulrajah, Artit UdomchaiAbstract:This research investigates strength development and the carbon footprint of Calcium Carbide Residue (CCR) and Fly Ash (FA) based geopolymer stabilized marine clay. Coode Island Silt (CIS), a soft and highly compressible marine clay present in Melbourne, Australia was investigated for stabilization with the CCR and FA geopolymers. CCR is an industrial by-product obtained from acetylene gas production, high in Ca(OH)2 and was used as a green additive to improve strength of the FA based geopolymer binder. The liquid alkaline activator used was a mixture of sodium silicate solution (Na2SiO3) and sodium hydroxide (NaOH). The influential factors studied for the geopolymerization process were Na2SiO3/NaOH ratio, NaOH concentration, L/FA ratio, initial water content, FA content, CCR content, curing temperature and curing time. The strength of stabilized CIS was found to be strongly dependent upon FA content and NaOH concentration. The optimal ingredient providing the highest strength was found to be dependent on water content. Higher water contents were found to dilute the NaOH concentration, hence the optimal L/FA increases and the optimal Na2SiO3/NaOH decreases as the water content present in the clay increases. The maximum strength of the FA geopolymer (without CCR) stabilized CIS was found at Na2SiO3/NaOH = 70:30 ratio and L/FA = 1.0 for clay water content at liquid limit (LL). The role of CCR on the strength of FA geopolymer stabilized CIS can be classified into three zones: inactive, active and quasi-inert. The active zone where CCR content is between 7% and 12% is recommended in practice. The 12% CCR addition can improve up to 1.5 times the strength of the FA geopolymer. The carbon footprints of the geopolymer stabilized soils were approximately 22%, 23% and 43% lower than those of cement stabilized soil at the same strengths of 400 kPa, 600 kPa and 800 kPa. The reduction in carbon footprints at high strength indicates the effectiveness of FA geopolymer as an alternative and effective green soil stabilizer to traditional Portland cement.
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Calcium Carbide residue alkaline activator for clay fly ash geopolymer
Construction and Building Materials, 2014Co-Authors: Chayakrit Phetchuay, Cherdsak Suksiripattanapong, Suksun Horpibulsuk, Avirut Chinkulkijniwat, Arul Arulrajah, Mahdi M DisfaniAbstract:Abstract Calcium Carbide Residue (CCR) and Fly Ash (FA) are waste by-products from acetylene gas and power plant production, respectively. The liquid alkaline activator studied in this research is a mixture of sodium silicate solution (Na 2 SiO 3 ), water and CCR. The primary aim of this research is to investigate the viability of using CCR, a cementitious waste material, as an alkaline activator and FA as a precursor to improve the engineering properties of a problematic silty clay to facilitate its usage as stabilized subgrade material. The influential factors studied are Na 2 SiO 3 /water ratio, FA replacement ratio, curing time, curing temperature and soaking condition for a fixed CCR content of 7%. Strength development is investigated via the unconfined compression test. Scanning Electron Microscopy (SEM) observation is used to explain the role and contribution of influential factors on strength development. CCR dissolves the silicon and aluminum in amorphous phase of FA and the Na 2 SiO 3 acts as a binder. The maximum soaked strength of the clay-FA geopolymer is found at Na 2 SiO 3 /water ratio of 0.6 and FA replacement ratio of 15%. The optimal Na 2 SiO 3 /water ratio is approximated from index test, which is a very practical approach. The clay-FA geopolymers with 40 °C curing exhibit higher strength than those with room temperature curing, indicating the possibility of using clay-FA geopolymer for pavement subgrade applications. The 7-day soaked strength at the optimal ingredient meets the strength requirement for subgrade materials specified by the local national road authority. CCR is found to be a sustainable alkaline activator for geopolymer stabilized subgrade materials, which will result in the diversion of significant quantities of this by-product from landfills.
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strength development in silty clay stabilized with Calcium Carbide residue and fly ash
Soils and Foundations, 2013Co-Authors: Suksun Horpibulsuk, Chayakrit Phetchuay, Avirut Chinkulkijniwat, Arnon CholaphatsornAbstract:Abstract Calcium Carbide residue (CCR) and fly ash (FA) are waste products from acetylene gas factories and power plants, respectively. The mixture of CCR and FA can produce a cementitious material because CCR contains a large amount of Ca(OH)2 while FA is a pozzolanic material. Soil stabilization by CCR is classified using three zones: active, inert and deterioration. In the active zone, the natural pozzolanic material in the soil is adequate to produce a pozzolanic reaction. Hence, the input of FA into this zone does not significantly improve strength. Strength in the inert zone can be significantly increased by adding FA. FA improves the densification and pozzolanic reaction. The deterioration zone is not recommended for use in practice, even with the input of FA. The unsoundness due to free lime hinders strength development. Although the soaked and unsoaked strengths depend mainly on the CCR and FA contents, most of the ratios of soaked strength to unsoaked strength vary between 0.45 and 0.65. It is proved that a mixture of CCR and FA can be used for soil stabilization instead of ordinary Portland cement. The possible mechanism regarding the control of strength development presented in this paper can be applied to other clayey soils stabilized with different cementitious materials produced from Ca(OH)2-rich and pozzolanic materials. This putative mechanism is also fundamental for further studies involving the development of rational dosage methodologies.
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soil stabilization by Calcium Carbide residue and fly ash
Journal of Materials in Civil Engineering, 2012Co-Authors: Suksun Horpibulsuk, Chayakrit Phetchuay, Avirut ChinkulkijniwatAbstract:Calcium Carbide residue (CCR) and fly ash (FA) are both waste products from acetylene gas factories and power plants, respectively. The mixture of CCR and FA produces a cementitious material because CCR contains a lot of Ca(OH)2, while FA is a pozzolanic material. This paper investigates the possibility of using this cementitious material (a mixture of CCR and FA) to improve the strength of problematic silty clay in northeast Thailand. The influential factors involved in this study are water content, binder content, CCR∶FA ratio, and curing time. The mechanism controlling the development of strength is also illustrated. Strength development is investigated using the unconfined compression test. A microstructural study using a scanning electron microscope and thermal gravity analysis is performed to understand the microstructural changes that accompany the influential factors. Both strength and microstructural investigations reveal that the input of CCR reduces specific gravity and soil plasticity; thus, t...