Effects of spent garnet on the compressive and flexural strengths of concrete

Sand is the non-renewable resource which has been over-exploited from rivers in sync with the rapid development of construction industries to produce concrete. This affected the morphology of rivers and interrupted the functionality of riverine ecosystems by pollution. Meanwhile, the unrecyclable spent garnets were disposed of on a large scale and led to waste pollution. Therefore, this study aimed to determine the compressive and flexural strengths of concrete consisting of spent garnet as sand replacement. The specimens were prepared with consisting of spent garnet as sand replacement by weight in 0%, 10%, 20%, 30% and 40%. They were tested under compressive strength test at the age of 7 and 28 days while flexural strength test was conducted on the 28days. The findings revealed that the workability of fresh concrete was enhanced by an incremental amount of spent garnet. However, the compressive and flexural strengths of concrete consisting of spent garnet were discerned to be lower than control samples at all levels of replacement. Overall, the replacement with 20% spent garnet showed the optimum compressive and flexural strengths. It is concluded that the usage of spent garnet is considered as a promising resource for reducing consumption of sand and thus, improving the environmental problems

Evaluation of acid attack on concrete containing spent garnet as partial sand replacement

This research studied the water absorption of concrete containing spent garnet and determine the durability of concrete containing spent garnet in acidic environment. The materials used along the experiment works were spent garnet, river sand, crushed stone, ordinary Portland cement and water. In this study, spent garnet were used as sand replacement with 0%, 10%, 20%, 30% and 40% in concrete mix designs. First and foremost, the water absorption test was conducted on three (3) set of water-curing cube specimens with dimension 100 mm cube for the plain concrete and for each percentage of spent garnet concrete mixes and was done in compliance with the BS 1881: Part122 (1983) specification. After that, the durability tests under 5% of hydrochloric acid attack and 5 % of sulphuric acid attack were conducted by preparing corresponding sets of concrete specimens which were three (3) set of 28 days water-curing specimens for each percentage of spent garnet in different acid immersion according to Standard ASTM C1898 – 20 while the compressive strength was under standard in BS EN:12390-3: 2019. In the end of the study, the physical appearances of the samples were observed and the weight loss for each sample was tested and recorded accordingly. From the results obtained, the highest percentage of water absorption of concrete was C20 which was 7.80%. However, the stronger average concrete strength of concretes from both acids with the achieved target compressive strength was concrete C20 but also with lowest weight loss. The concrete containing with 20% of spent garnet had better acid resistant in terms of visual assessment not only toward sulphuric acid attack but also toward hydrochloric acid attack. The application of 20% of spent garnet as sand replacement was hence can provide stronger acid resistant in maintaining the supporting strength of concrete. In conclusion, the durability of normal concrete should be investigated over a longer length of time to mimic the real-world circumstance in which a structure is erected

Mechanical properties of oil palm waste lightweight aggregate concrete with fly ash as fine aggregate replacement

Environmental degradation posed by fly ash (FA) disposal from coal power plants and shell from the oil palm fruit processing trade is non-trivial. The destruction of flora and fauna resulting from the extraction of river sand and granite aggregate from the green hills in an uncontrolled fashion for the production of concrete that is widely used in the construction industry does also require a solution. Introducing oil palm shell (OPS) and fly ash as a mixing ingredient in zero granite lightweight aggregate concrete production is an appealing notion. Success in utilising the available solid waste would reduce dumping of these by-products and consumption of natural aggregates, thus ensuring the preservation of the environment for the future generation. Therefore, this research explores the influence of FA content as sand replacement towards the mechanical and durability properties of agro-based lightweight concrete. Five concrete mixes with FA quantity ranging from 0% to 40% were prepared. Two forms of curing procedure were practised viz. water and indoor air curing. All the mixes were tested for fresh and hardened characteristic as well as sulphate resistance. The test results demonstrated that a substitution of 10% sand with FA yielded better mechanical properties and denser concrete with more resistant to sulphate attack in comparison to the control mix. The utilisation of two industrial waste materials such as FA and OPS may address the issue of paucity of natural resources that is experienced in the construction industry, particularly in the case of natural granite and river sand

Assessment of acid attack on concrete containing spent garnet as partial sand replacement

Excessive sand mining for concrete production and disposal spent garnet waste from industrial activity causes environmental degradation. These degraded materials need to be inclined with other ways such as being a substitution of fine aggregate thus, preserving the environmental resources. The purpose of this study is to investigate the durability aspect of concrete containing spent garnet in acidic environment. Spent garnet was used as partial sand replacement with 0%, 10%, 20%, 30% and 40% in each of the concrete mixes designed respectively. Initially, the water absorption test was conducted on sets of 3 water-cured concrete cubes for the plain concrete and also for each percentage of spent garnet concrete mixes. Furthermore, the durability tests under 5% of hydrochloric acid and 5% of sulphuric acid solutions were conducted. Sets of concrete specimens which were 3 set of 28 days water-curing specimens for each percentage of spent garnet in each type of acid immersion have been evaluated respectively. Additionally, another set of concrete specimens containing 3 cubes for each spent garnet content was cured in water for 56 days for the comparison purposes. At the end of the study, the highest percentage of water absorption was concrete mix of 20% sand replaced with spent garnet (C20). Other than that, the stronger average concrete strength of concretes from both acids with the achieved target compressive strength was concrete C20 which having 30.8MPa and 19.3MPa for each acid, respectively. The concrete containing 20% of spent garnet had better acid resistant in terms of visual assessment not only towards sulphuric acid attack but also towards hydrochloric acid attack. Conclusively, the utilization of spent garnet in concrete mixture could bring good expectation as partial sand replacement for construction industry resulting of conserving the natural resources

Properties of high strength concrete containing spent garnet as sand

Spent garnet is a waste resulting from abrasive media known as garnet and disposed into the landfill which can become threat to the environment. Meanwhile, the step of substituting sand by spent garnet can reduce sand exploitation activities which have been ongoing to fulfil the continuous development and construction. This work attempts to investigate the mechanical properties of specimens made of concrete that contains spent garnet. This new material replaces sand partially at different percentages of 10% and 20% by weight. The compressive strength test as well as splitting tensile test have been both conducted after 7 days and 28 days water curing. The results show an improvement of the strength during the compressive test. The increment appears to be in positive relationship with the replacement percentage. Meanwhile, splitting tensile strength testing shows that 20% performs better than 10% sand replacement. In conclusion, the inclusion of spent garnet in reasonable amount to take place instead of sand has improved the concrete's properties

Mechanical properties and acid resistance of oil palm shell lightweight aggregate concrete containing coal bottom ash

Excessive use of natural river sand causes degradation of river environment scenery and water quality as well as certain flora and fauna in the area. At the same time, continues generation of by-product from palm oil industry and coal power plants namely oil palm shell and coal bottom ash calls for the utilization of these waste in material production rather than disposing it as waste. The present research investigates the mechanical properties and acid resistance of oil palm shell lightweight aggregate concrete containing coal bottom ash as partial sand replacement. Four types of concrete mixes were casted by using coal bottom ash as partial sand replacement from 0%, 10%, 20%, and 30% by weight of sand. All specimens were air cured until the testing age. The compressive strength and splitting tensile strength of concrete were tested at 7, 28 and 60 days. The resistance of specimen against acid attack was evaluated by measuring the mass loss and compressive strength after concrete cubes exposed to sulphuric acid solution. The results show that OPS lightweight aggregate concrete exhibit higher compressive and splitting tensile strength also enhanced acid resistance upon inclusion of 10% of coal bottom ash as sand replacement

Long term prediction of pipeline corrosion under tropical seabed sediment

The corrosion of pipeline steels buried under seabed sediment is not fully predictable, since there are many parameters affecting the pipeline at different degrees. In relation to that, corrosion growth predictive model based on long term experimental study is of great demand to assist in making suitable pipeline integrity decisions. Therefore, research has been conducted to investigate the metal loss behaviour and corrosion mechanism of pipeline steel under seabed sediment conditions. Then, this study developed a predictive model for corrosion under seabed sediment and highlighted corrosion parameters which presented in tropical climate. Two corrosion models were proposed; one based on the results of a long term exposure of steel coupons to the real field condition. Furthermore, another descriptive model was developed using response surface methodology. The most common applied model used to predict corrosion loss is the power law model (P = ktn), where t is exposure time, and k and n are constant regression of the sediment parameters. Carbon steel coupons were buried in seabed sediment up to two years period. The sediment samples were analysed for its contents and properties. The descriptive model was constructed with aid of Statistica 6.0 software for the data obtained from the laboratory experiment. The results were analysed using statistical methods such as correlation test analysis (CTA), principal component analysis (PCA), multiple linear regression (MLR) and ANOVA (analysis of variance). From the analysis, the extraction of sediment variables related to k and n were successfully obtained. In order to get the best fit of predictive model, the extracted variables are modelled using MLR and embedded in the power law equation. Good curve fitting results are obtained between the actual test data and the proposed models. With consideration of pipelines integrity, the prediction of metal loss due to corrosion in SBS environment using the developed power-law model is considered satisfactory with R2 score of 0.76. The corrosion model based on data from the laboratory has yielded reasonable prediction of metal mass loss with R2 score of 0.83. Noticeably, several sediment factors play an important role in corrosion process and thus determine the corrosion severity. Corrosion growth models have been developed and proposed to predict corrosion progress for steel pipelines buried under seabed sediment. This research has introduced innovative ways to model the corrosion growth for seabed sediment environment. Moreover, intensive statistical analysis has been utilised to determine the level of influence of sediment parameters towards corrosivity. The models enable the prediction of metal mass loss, thus assessing the corrosivity of seabed sediment condition for Malaysian tropical climate

Performance of High Strength POFA Concrete in Acidic Environment

Malaysia as the world’s largest exporter of palm oil has been facing problem in disposing palm oil fuel ash, a by-product of palm oil mill since many years ago. The discovery made by researchers of Universiti Teknologi Malaysia last century in revealing the potential of this finely ground waste as a partial cement replacement in normal concrete has stem efforts towards studying the possibility of using it in high strength concrete production. This paper illustrates the durability aspect of high strength concrete produced using POFA of different fineness when exposed to acidic environment. Two POFA concrete mixes with different fineness termed (POFA 45 and POFA 10) at 20% replacement level by weight of cement and an OPC concrete mix functioning as control specimen termed Po was considered in this study. All the specimens were subjected to water curing for 28 days before immersed in the hydrochloric solution having pH 2 for 1800 hours. The progressive deterioration was evaluated through mass changing of the specimens, visual inspection and relative compressive strength determinations. Conclusively, the study found that increase in the POFA fineness enhances the resistance of high strength POFA concrete towards acid attack

Corrosion of steel under simulated condition of offshore seabed sediment

Steel pipelines subjected to corrosion at any time when placed in adverse environments. Marine sediments are corrosive in nature and can allow severe damage to steel facilities underneath. There had been incidents to indicate the potential of oil and gas pipelines that carry hazardous materials to cause financial damage, environmental issues and pollution. This paper studies the behaviour of corrosion in pipelines steel when placed in seabed sediment environment. Simula-tions on sediment of different characteristics have been carried out to examine their effects on steel coupons buried in them. Consequently, the corrosion rate of the steel specimens were determined via weight loss technique. The results show that metal weight loss increases as the duration of exposure to seabed sediment environment becomes longer. The corrosion order for types of sediment existing in seabed simulated environment is found as follows, fine sand < medium sand < clay < coarse sand. In conclusion, the indoor simulation of seabed sediment can be conducted and is found relatively reliable to explain some corrosion phenomena for a short period studies