202 research outputs found
Durability Performance of Palm Oil Fuel Ash Cement Based Aerated Concrete in Marine Environment
The ever popular issue on environmental preservation and sustainability all over the world has lead towards the innovation of new materials from either industrial or
agricultural waste. Malaysia being one of the leading producers of palm oil has been conducting numerous researches to discover the various potentials of by-products generated by palm oil mills. The current findings revealed that palm oil fuel ash (POFA) produced in the mills can be used for producing a new alternative lightweight construction material known as POFA cement based aerated concrete having enhanced strength than specimen produced using 100% ordinary Portland cement.
Since, the performance this material in marine environment is unknown, this paper presents and discusses the result on the strength performance of this lightweight concrete upon exposure to sea water for one year. The concrete cubes were prepared and subjected to water curing for 28 days before immersed in sea water. The compressive and flexural strengths of the specimens were tested at 3, 6 and 12 month following the procedures stated in BS 1881: Part 116 and ASTM C293-79 respectively. The study found that integration of POFA as partial cement replacement
in aerated concrete enhances the performance of concrete in sea water environment
Soluble pozzolanic materials from coal bottom ash as cement replacement material
Nowadays, intensive research in production of highly reactive pozzolanic materials from
industrial waste to replace cement is crucial. This action expected to increase industrial waste
recycling rate and at the same time reduce extraction of non-renewable resources of limestone.
Unique characteristics of coal bottom ash as one of the industrial based pozzolan gained less
popularity because of its low reactivity and heavy metal leaching due to conventional method used
for disposal. Therefore, an alternative approach was deliberated in this research to utilize coal
bottom ash into soluble form and enhance the quality of bottom ash as pozzolanic material. Coal
bottom ash after the acid washing with optimum parameter was then undergoes solution-gelification
process with various alkali based solution for 2 hours soaking durations. The conversion of coal
bottom ash into soluble silica in this study demonstrates good pozzolanic performance in a state of
siliceous gel pozzolan compared to the raw ones. 5% of cement replacement by soluble silica from
CBA shows good strength development from early and later age. The physical dispersion effect is
the cumulative effect of enhancement cement hydration due to the availability of increased the
nucleation sites on soluble silica particles
Effect of Curing Regime on Compressive Strength of Aerated Concrete Containing Palm Oil Fuel Ash as Partial Sand Replacement
Issues on preservation of natural river sand from being used excessively in concrete industry has led to the efforts of utilizing palm oil fuel ash, a by-product from palm oil industry as partial sand replacement in production of aerated concrete. This paper reports the effect of curing regime on compressive strength development of aerated concrete containing palm oil fuel ash as partial cement replacement. Two types of mixes were used in this experimental work namely plain aerated concrete acting as control specimen and aerated concrete containing 30% palm oil fuel ash as partial sand replacement. Concrete cubes were subjected to different types of curing namely initial water curing for 7 days followed by air curing, water curing and air curing until the testing date. The compressive strength test was conducted in accordance to BS EN 12390-3 at 7, 14, 28 and 90 days. Application of water curing is the most suitable method to be applied to ensure better strength development in aerated concrete containing POFA as partial sand replacement. Continuous presence of moisture promotes better hydration and pozzolanic reaction leading to formation of extra C-S-H gel making the concrete denser and exhibit higher compressive strength
Development of Sucrose and Citric Acid as the Natural Based Admixture for Fly Ash Based Geopolymer
Geopolymer is the state of the art binder in concrete technology. It utilizes alkaline solution to activate alumina and
silica precursors from source material and forms aluminosilicate-based binding material. Nevertheless, the presence
of high calcium content in the source material can reduce the performance of geopolymer binder, particularly in terms
of its workability performance. The available commercial admixture cannot provide significant improvement to the
rapid setting time generated by high calcium in geopolymer system. This research studied the effect of sucrose and
citric acid as the proposed natural admixture in fly ash based geopolymer binder. Based on Vicat setting time result,
these materials behave oppositely in fly ash based geopolymer paste. Sucrose tends to increase the setting time of
geopolymer paste, while citric acid has an accelerating effect. An unexpected trend is also shown from the relation
between porosity and compressive strength of hardened specimen. It appears that the rapid production of geopolymer
gels to fill the water-filled voids was not followed by the quality of gel structure. However, these results have
presented an encouraging prospect for natural-based material to be developed as the admixture for geopolymer
concrete
Properties of concrete containing ground palm oil fuel ash as fine aggregate replacement
Environmental degradation resulting from increasing sand mining activities and disposal of palm oil fuel ash (POFA), a solid waste generated from palm oil mill needs to be resolved. Thus, the present research investigates the effect of ground palm oil fuel ash as partial fine aggregate replacement on workability, compressive and flexural strength of concrete. Five mixtures of concrete containing POFA as partial sand replacement designed with 0%, 10%, 20%, 30% and 40% of POFA by the weight of sand were used in this experimental work. The cube and beam specimens were casted and water cured up to 28 days before subjected to compressive strength and flexural strength testing respectively. Finding shows that concrete workability reduces as the amount of POFA added become larger. It is worth to note that 10% of POFA is the best amount to be used as partial fine aggregate replacement to produce concrete with enhanced strength
Concrete industry, environment issue, and green concrete: A review
Concrete is the second most utilized substance around the world behind the water. The aim of this paper is to review the environmental effect of concrete industry. It has been found that the environmental impact of concrete industry is severe in various environmental categories as global warming, depletion of ozone layer, and acidification of soil and water bodies. Moreover, concrete industry affects ecosystems and alters hydrogeological and hydrological systems. Green concrete has become increasingly popular among researchers and academics in recent years, although it is still in its infancy. This article examines the environmental impact of waste materials such as fly ash, silica fume, and slag as partial or complete replacements for cement, and of waste and recycled material as aggregates. It shows that the negative environmental effect of the concrete industry can be minimized by using these waste materials in the concrete production
Potential of waste material as coarse aggregates for lightweight concrete production: A sustainable approach
In recent times, there has been growing interest in utilizing waste materials as coarse lightweight aggregates in the production of lightweight aggregate concrete. This approach has been gaining momentum as it has the potential to address the environmental concerns that come with conventional construction practices. The objective of this review paper is to evaluate the viability and potential of waste materials as coarse lightweight aggregates for producing lightweight aggregate concrete. This paper reviews the current research on various types of waste materials, including waste plastic, recycled concrete aggregate, slag, fly ash, and expanded polystyrene, as potential candidates for coarse lightweight aggregates. The paper highlights the properties and characteristics of these waste materials and their suitability for use as coarse lightweight aggregates. Additionally, the evaluation explores the mechanical characteristics of lightweight aggregate concrete that is generated using waste materials as coarse lightweight aggregates. Specifically, it compares the compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity of lightweight aggregate concrete that includes waste materials with those of typical concrete. Furthermore, the paper discusses the sustainability benefits of using waste materials as coarse lightweight aggregates. By using waste materials in construction, not only are resources conserved, but waste is also diverted from landfills, reducing the negative impact on the environment. In conclusion, this review paper demonstrates that the use of waste material as coarse lightweight aggregate for lightweight aggregate concrete production is a viable and sustainable approach. The application of waste materials as coarse lightweight aggregates in lightweight aggregate concrete demonstrates mechanical characteristics that are similar to traditional concrete. Moreover, utilizing waste materials in this manner provides environmental advantages. This study offers valuable insights into the implementation of waste materials in construction, and it emphasizes the possibility of further exploration and advancement in this domain. For this review, a total of 15 articles were analyzed, with publication dates ranging from 2005 to 2021. The study contributes to several Sustainable Development Goals (SDG 9/11/12/13) set by the United Nations such as providing insights into the role of industry, innovation, infrastructure, sustainable cities, responsible consumption, production practices, and climate action
Properties of cement sand brick containing finely crushed cockle shell as partial fine aggregate replacement
Research towards producing environmental friendly cement sand brick stems out from the environmental problem caused by dumping of cockle shell by cockle trade and the increasing river sand mining. This paper discusses the effect of finely crushed cockle shell as partial fine aggregate replacement towards compressive strength, flexural strength and water absorption of cement sand brick. A total of six mixes have been used in this experimental work. Brick produced 100% river sand is considered as control specimen. Another type of mix was prepared by adding a range of crushed cockle shell that is 10%, 20%, 30%, 40% and 50% as partial fine aggregate replacement. All mixes were subjected to water curing until the testing age. Both compressive strength test and flexural strength were conducted at 7, 28 and 60 days. The findings shows that integration of 30% finely crushed cockle shell increase the compressive strength and flexural strength of brick. The same mix also exhibits the lowest water absorption value. Utilization of crushed cockle shell as partial fine aggregate replacement that acts as filler makes the internal structure of brick become denser and stronger. Success in incorporating cockle shell waste in brick production would assist in reducing quantity of shell disposed by cockle trade as solid waste and lower the consumption of natural river sand
Study on Durability Performance of Concrete Containing Laterite Aggregates
This paper addresses the durability performance of concrete containing laterite aggregate against corrosion, acid attack and carbonation. Two types of mixes were used, that is plain concrete (0% laterite aggregate) and another one, produced by integrating 20% of laterite aggregate as partial coarse aggregate replacement. The corrosion resistance test was conducted by immersing the 28 days water cured specimens in sodium chloride for 1, 7 and 15 days. The steel bars were then connected to the data logger to determine the corrosion potential of each specimen. The acid resistance of specimens were investigated by immersing it in hydrochloric acid solution and the mass of cubes were measured at every 100 hour until 1800 hour. Carbonation depth was determined by spraying phenolphthalein indicator on broken surface of prism with curing age up to 1 year. The corrosion potential of both types of concrete rose as experimental period become longer. The acid resistance results show the difference in total mass loss of laterite concrete and control specimen is less than 5%. Carbonation results of the specimens are also close to each other. Utilization of 20% laterite aggregate as partial coarse aggregate replacement influences the resistance of concrete upon corrosion effect, acid attack and carbonation
Influence of mineral admixtures on the properties of self-compacting concrete: An overview
Mineral admixtures are often utilized in Self-Compacting Concrete (SCC) mixtures to provide stability and resistance to bleeding and segregation throughout transportation and placement. Additionally, these more refined materials help in lowering building costs and reducing the use of main resources. SCC is an innovative method of concrete, which is placed and compacted without the use of vibration. As a result, the concrete mixture has the ability to flow under its self-weight to fully fill formwork and achieve total compaction even when reinforced by crowded reinforcement. However, self-compacting concrete is not cost-effective, which results in the use of large amounts of ordinary cement and chemical admixtures. The utilization of mineral admixtures, including silica fume, ground granulated blast furnace slag, fly ash, and coal bottom ash, is an alternative method to decrease the high cost of self-compacting concrete - it is a term, which refers to the components that have been finely divided and added to concrete during the mixing process. Furthermore, the utilization of admixtures in the fabrication of self-compacting concrete has shown that it helps in lowering the heat of hydration. In addition, the inclusion of admixtures reduces the necessity for chemical admixtures that increase viscosity in concrete mixtures. This study aims to provide an overview of the previously conducted studies on mineral admixtures, which are utilized in SCC. Moreover, the study aims to discuss the durability and mechanical performance of SCC
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