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Arnon Chaipanich - One of the best experts on this subject based on the ideXlab platform.

  • utilization of ceramic waste as fine aggregate within portland cement and fly ash Concretes
    Cement & Concrete Composites, 2010
    Co-Authors: Pincha Torkittikul, Arnon Chaipanich
    Abstract:

    Abstract The aim of this research work was to investigate the feasibility of using ceramic waste and fly ash to produce mortar and Concrete. Ceramic waste fragments obtained from local industry were crushed and sieved to produce fine aggregates. The measured Concrete properties demonstrate that while workability was reduced with increasing ceramic waste content for Portland cement Concrete and fly ash Concrete, the workability of the fly ash Concrete with 100% ceramic waste as fine aggregate remained sufficient, in contrast to the Portland cement Control Concrete with 100% ceramic waste where close to zero slump was measured. The compressive strength of ceramic waste Concrete was found to increase with ceramic waste content and was optimum at 50% for the Control Concrete, dropping when the ceramic waste content was increased beyond 50%. This was a direct consequence of having a less workable Concrete. However, the compressive strength in the fly ash Concrete increased with increasing ceramic waste content up to 100%. The benefits of using ceramic waste as fine aggregate in Concrete containing fly ash were therefore verified.

  • compressive strength microstructure and thermal analysis of autoclaved and air cured structural lightweight Concrete made with coal bottom ash and silica fume
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010
    Co-Authors: Watcharapong Wongkeo, Arnon Chaipanich
    Abstract:

    Abstract This research investigated the compressive strength, microstructure and thermal analysis of autoclaved and air cured structural lightweight Concrete made with coal bottom ash and silica fume. The results show that bottom ash lightweight Concrete autoclaved for 6 h gives compressive strength similar to the bottom ash lightweight Concrete air cured for 28 days and found that the compressive strength of both bottom ash lightweight Concrete increased when silica fume was added to the mix. The highest compressive strength obtained for all mixes was found when coal bottom ash was used at 20% with the addition of silica fume at 5% and that this strength value is significantly higher than that of Portland cement Control. The thermal conductivity of all bottom ash lightweight Concrete at 28 days and those autoclaved for 6 h were found to be slightly higher than that of Portland cement Control Concrete. Air cued hydration products such as ettringite, calcium silicate hydrate and gehlenite hydrate were detected using thermogravimetric analysis. The tobermorite phase detected in autoclaved bottom ash Concrete with silica fume was found to give denser microstructure than the fibrous-like C–S–H phases detected in Portland cement Control Concrete.

V. Revathi - One of the best experts on this subject based on the ideXlab platform.

  • Microstructural Properties of Alkali-Activated Metakaolin and Bottom Ash Geopolymer
    Arabian Journal for Science and Engineering, 2020
    Co-Authors: M. Logesh Kumar, V. Revathi
    Abstract:

    This paper presents a study on the use of alkali-activated metakaolin (MK) and Bottom Ash (BA) blend in geopolymer Concrete. A preliminary attempt was made on alkali-activated metakaolin and bottom ash-based geopolymer (MK–BA-GPM) mortar with river sand as fine aggregate to find a suitable mix to produce geopolymer Concrete (GPC). The liquid alkaline activator is a combination of sodium silicate and sodium hydroxide solution. The molarity of NaOH was 8 M. Molar ratio of Na_2O and SiO_2 was 2, and ambient curing mode was selected. Also, M30 grade Control Concrete was made using OPC and cured in water. Further, GPC and Control Concrete specimens were tested for compressive strength, split tensile, flexural strength and modulus of elasticity. Also, XRD, SEM and EDAX studies were carried out to analyse element/mineral compounds present and the microstructure and morphological characteristics of GPC to substantiate the strength development. MK–BA GPC demonstrated 49% higher compressive strength than that of Control Concrete at 28 days. More so, the early as well as later strength gain of GPC was remarkably higher than that of OPC. Strength was due to densification of microstructure over a period of time and due to the formation of additional crystalline phases in geopolymer Concrete.

  • Microstructural Properties of Alkali-Activated Metakaolin and Bottom Ash Geopolymer
    Arabian Journal for Science and Engineering, 2020
    Co-Authors: M. Logesh Kumar, V. Revathi
    Abstract:

    This paper presents a study on the use of alkali-activated metakaolin (MK) and Bottom Ash (BA) blend in geopolymer Concrete. A preliminary attempt was made on alkali-activated metakaolin and bottom ash-based geopolymer (MK–BA-GPM) mortar with river sand as fine aggregate to find a suitable mix to produce geopolymer Concrete (GPC). The liquid alkaline activator is a combination of sodium silicate and sodium hydroxide solution. The molarity of NaOH was 8 M. Molar ratio of Na2O and SiO2 was 2, and ambient curing mode was selected. Also, M30 grade Control Concrete was made using OPC and cured in water. Further, GPC and Control Concrete specimens were tested for compressive strength, split tensile, flexural strength and modulus of elasticity. Also, XRD, SEM and EDAX studies were carried out to analyse element/mineral compounds present and the microstructure and morphological characteristics of GPC to substantiate the strength development. MK–BA GPC demonstrated 49% higher compressive strength than that of Control Concrete at 28 days. More so, the early as well as later strength gain of GPC was remarkably higher than that of OPC. Strength was due to densification of microstructure over a period of time and due to the formation of additional crystalline phases in geopolymer Concrete.

  • Potential Reuse of Treated Textile Effluent in Fly Ash Concrete
    Journal of Testing and Evaluation, 2019
    Co-Authors: P. Ramya, V. Revathi, S. Sivamurthy Reddy
    Abstract:

    In a preliminary effort to deal with the present fresh water demand in the construction industry, this article examines the potential reuse of textile effluent as mixing water in making fly ash Concrete. The effluents were collected from a textile industry at different stages of treatment, such as Collection Tank Effluent, Effluent after Anaerobic Treatment (EAT), Tertiary Treatment Effluent, and Reverse Osmosis Feed Effluent. The collected effluent samples have been analyzed to establish physicochemical characteristics and their effects on the properties of Concrete, such as compressive strength, split tensile strength, and flexural strength. Higher salt content in effluent mix water significantly increased the final setting time of the binder. Furthermore, the workability of the Concrete made with effluent mix water is relatively higher than that of the Control Concrete mix. Also, Concrete mixes made with textile effluent mix water demonstrated greater strength than that of the Control Concrete. Furthermore, EAT mixes have exhibited maximum compressive strength compared with other mixes and also had superior durability compared with the Control Concrete mix. The higher strength can be attributed to the nucleation effect caused by the presence of a high concentration of total solids in the effluent. However, this Concrete can be recommended for applications of plain cement Concrete, such as pavements, industrial floors, and curbs/gutters.

  • Influence of textile effluent on the Reaction, Structure and Properties of
    Journal of Advances in Chemistry, 2016
    Co-Authors: P. Ramya, V. Revathi
    Abstract:

    The transformation of industrial wastes into useful products attracts more researches to work upon for sustainable of natural resources. In this paper, industrial wastes such as treated textile effluent and fly ash were used in the preparation of plain cement Concrete with the intention of reducing the environmental pollution caused by these materials. The partially treated textile effluent was used as mixing water and fly ash was used as 30% partial replacement by weight of cement in Concrete. The textile effluents were collected after anaerobic treatment and tertiary treatment from textile industry. Class F Fly ash was collected from Mettur thermal power plant. The physical and chemical properties of treated textile effluent were studied. The Control Concrete was prepared with potable water available in the laboratory. Experimental test was performed for compressive strength of Concrete at 28 days. The powdered Concrete samples were examined through infrared spectroscopy, X-ray diffraction and scanning electron microscopy to study the microstructure of Concrete. The compressive strength test results revealed that anaerobic effluent water (AAE) Concrete accomplished higher compressive strength than Control Concrete. This was also in affirmation with microscopic analysis in which the formations of hydration products were well established when compared to Control Concrete.

V M Malhotra - One of the best experts on this subject based on the ideXlab platform.

  • PERFORMANCE OF STEEL REINFORCEMENT IN PORTLAND CEMENT AND HIGH-VOLUME FLY ASH ConcreteS EXPOSED TO CHLORIDE SOLUTION
    Aci Materials Journal, 1999
    Co-Authors: J J Beaudoin, M. H. Zhang, V M Malhotra
    Abstract:

    This paper describes the performance of steel reinforcement in portland cement and high-volume fly ash (HVFA) Concretes exposed to a chloride solution. A number of large slabs (833-by-600-by-153 mm) were cast from six air-entrained Concrete mixtures. Four of these mixtures were made with normal portland cement with a water-cement ratio (w/c) ranging from 0.32 to 0.76. The remaining two mixtures were made with the HVFA Concrete with a w/(c + FA) of 0.32. The steel reinforcing bars were placed in Concrete with cover thickness ranging from 13 mm to 76 mm. The Concrete slabs were ponded with a 3.4% sodium chloride solution for a period of 6 months; and half-cell potential, linear polarization, and AC impedance techniques were applied to monitor the progress of the corrosion of steel reinforcement. The results indicate that the performance of the reinforcing steel bars in the HVFA Concrete after 6 months of ponding with a 3.4% sodium chloride solution was excellent. No significant steel corrosion took place on the reinforcing bars embedded in the HVFA Concrete, even with 13 mm Concrete cover. This performance of HVFA Concrete is equivalent to that of the Control Concrete with a w/c of 0.32 and is better than the Control Concrete with w/c > or = 0.43. Significant corrosion rates were observed for the reinforcing bars embedded in Control portland cement Concrete with w/c > or = 0.43. As expected, the poorest performance was of the Control Concrete with a w/c of 0.76, where even the reinforcing bars with 51 mm cover exhibited corrosion.

  • Characteristics of a thermally activated alumino-silicate pozzolanic material and its use in Concrete
    Cement and Concrete Research, 1995
    Co-Authors: Min-hong Zhang, V M Malhotra
    Abstract:

    Abstract This paper presents the results of the physical and chemical properties of a thermally activated alumino-silicate material (MK), and deals with the properties of fresh and hardened Concrete incorporating this material. The properties of fresh Concrete investigated included workability, bleeding, setting time, and autogenous temperature rise. The properties of the hardened Concrete investigated included compressive, splitting-tensile and flexural strengths, Young's modulus of elasticity, drying shrinkage, resistance to chloride-ion penetration, freezing and thawing, and saltscaling resistance. The properties of the MK Concrete were also compared with those of the Control portland cement Concrete and the silica fume Concrete. The test results indicate that the MK material is highly pozzolanic and can be used as a supplementary cementing material to produce high-performance Concrete. Although it requires a higher dosage of the superplasticizer and air-entraining admixture compared with that of the Control Concrete, the MK Concrete can be produced with satisfactory slump, air content, and setting time. The Concrete incorporating 10% MK had higher strength at all ages up to 180 days compared with the Control Concrete; in comparison with the silica fume Concrete the MK Concrete showed a faster strength development at early ages, but had lower strength after 28 days. At 28 days, the MK Concrete had somewhat higher splitting-tensile and flexural strengths, Young's modulus of elasticity, and lower drying shrinkage compared with that of the Control and the silica fume Concretes. The resistance of the MK Concrete to the chloride-ion penetration was significantly higher than that of the Control Concrete, but similar to that of the silica fume Concrete. The MK Concrete showed excellent performance in the freezing and thawing test. The performance of the MK Concrete subjected to the de-icing salt scaling test was similar to that of the silica fume Concrete, but marginally inferior to the Control Concrete.

  • LONG-TERM STRENGTH DEVELOPMENT OF SILICA FUME Concrete
    1992
    Co-Authors: G G Casrette, V M Malhotra
    Abstract:

    This paper presents results of an investigation dealing with the long-term strength development of silica fume Concrete. The study concluded that under water-curing conditions both the Control and silica fume Concretes show gain in strength with age, with both Concretes reaching similar strength levels after 3.5 years. However, continuous air-curing adversely affects the long-term compressive strength development of both types of Concrete. This effect is considerably more marked for silica fume Concrete than for the Control Concrete, especially at W/C plus SF of 0.30 and 0.40.

P S Kumar - One of the best experts on this subject based on the ideXlab platform.

  • study on reinforced lightweight coconut shell Concrete beam behavior under shear
    Materials & Design, 2013
    Co-Authors: K Gunasekaran, R Annadurai, P S Kumar
    Abstract:

    Lightweight Concrete has been produced using crushed coconut shell as coarse aggregate. The shear behavior of reinforced Concrete beam made with coconut shell is analyzed and compared with the normal Control Concrete. Eight beams, four with coconut shell Concrete and four with normal Control Concrete were fabricated and tested. Study includes the structural shear behavior, shear capacity, cracking behavior, deflection behavior, ductility, strains in Concrete and in reinforcement. It was observed that the shear behavior of coconut shell Concrete is comparable to that of other lightweight Concretes. The results of Concrete compression strain and steel tension strain showed that coconut shell Concrete is able to achieve its full strain capacity under shear loadings. However, the failure zones of coconut shell Concrete were larger than for Control Concrete beams.

Rafat Siddique - One of the best experts on this subject based on the ideXlab platform.

  • effect of coal bottom ash as partial replacement of sand on workability and strength properties of Concrete
    Journal of Cleaner Production, 2016
    Co-Authors: Malkit Singh, Rafat Siddique
    Abstract:

    Abstract Large quantity (35 million tons) of coal bottom ash is produced by thermal power plants in India. The present method of disposal of coal bottom ash on open land is the main cause of an environment hazard for the surrounding community. As utilization of coal bottom ash can help in alleviating environmental problems, thus the present work was done to explore the possibility of its use as sand replacement in Concrete manufacturing. Two types of Control Concrete mixtures to develop 28 d compressive strength of 38 MPa designated as Concrete ‘A’ and 34 MPa designated as Concrete ‘B’ were made with river sands having different fineness of modulus. In both grades of Concrete mixtures, sand was replaced with coal bottom ash at 20, 30, 40, 50, 75 and 100% levels. Workability and bleeding of Concrete decreased on use of coal bottom ash as fine aggregate. Test results show that compressive and splitting strength of Concrete mixture ‘A’ did not changed significantly when sand having fineness modulus of 1.97 was replaced with coal bottom ash. However, in case of Concrete mixture ‘B’, when coal bottom ash was used as replacement of sand having fineness modulus of 2.58, the compressive and splitting tensile strength of bottom ash Concrete decreased at early curing age. After 90 d of curing age, compressive and splitting tensile strength of bottom ash Concrete mixtures was almost comparable to that of Control Concrete mixture. Bottom ash Concrete mixtures displayed lower modulus of elasticity and abrasion resistance as compared to Control Concrete mixture. Abrasion resistance of bottom ash Concrete mixtures improved significantly with age. Pulse velocity through bottom ash Concrete mixtures indicates that good quality Concrete can be made with coal bottom ash as replacement of either type of sand.

  • Effect of Low-Calcium Coal Bottom Ash as Fine Aggregate on Microstructure and Properties of Concrete
    ACI Materials Journal, 2015
    Co-Authors: Malkit Singh, Rafat Siddique
    Abstract:

    This study evaluates the strength and durability properties of Concrete incorporating low-calcium coal bottom ash as partial or total replacement of fine aggregate. The test results indicate that at a fixed water-cement ratio (w/c), workability, 28-day compressive strength, splitting tensile strength, and pulse velocity through Concrete decreased with the increase in coal bottom ash content. With age, the compressive strength of bottom ash Concrete improved at a faster rate compared to that of a Control Concrete. Bottom ash Concrete achieved compressive and splitting tensile strengths comparable to that of the Control Concrete at 180 days and 90 days, respectively. At 28 days and up to 75% sand replacement level, chloride ion penetration increased with increase in coal bottom ash content in Concrete. However, with age, opposite results in respect of chloride ion penetration were observed. Bottom ash Concrete and the Control Concrete showed almost identical performance under external sulfate and acid attack. Microstructural analysis revealed that pozzolanic activity of coal bottom ash in Concrete started after 28 days. X-ray diffraction spectrums indicate that the phase composition of powder Concrete paste was not changed qualitatively; however, the change in phase proportions was observed on use of coal bottom ash in Concrete. Bottom ash Concrete displayed slightly lower resistance to abrasion as compared to Control Concrete.