Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 19 of 19
Full-Text Articles in Engineering
Effects Of Heat Treatment On Oil Palm Shell Coarse Aggregates For High Strength Lightweight Concrete, Hilmi Mahmud
Effects Of Heat Treatment On Oil Palm Shell Coarse Aggregates For High Strength Lightweight Concrete, Hilmi Mahmud
Hilmi Mahmud
In this study, the effects of heat treatment on oil palm shell (OPS) coarse aggregates are evaluated for high strength lightweight concrete (HSLWC). OPS coarse aggregates are subjected to heat treatment at two temperature settings (60 and 150. °C) and duration of heat treatment (0.5 and 1. h). The reduction in density is found to be within the range of HSLWC when heat-treated OPS aggregates are added into the oil palm shell concrete (OPSC). The results reveal that workability of the OPSC increases with an increase in temperature and duration of heat treatment of the OPS aggregates. It is found …
Effects Of Using Silica Fume And Polycarboxylate-Type Superplasticizer On Physical Properties Of Cementitious Grout Mixtures For Semiflexible Pavement Surfacing, Hilmi Mahmud
Hilmi Mahmud
Semi-flexible pavement surfacing is a composite pavement that utilizes the porous pavement structure of the flexible bituminous pavement, which is subsequently grouted with appropriate cementitious materials. This study aims to investigate the compressive strength, flexural strength, and workability performance of cementitious grout. The grout mixtures are designed to achieve high strength and maintain flow properties in order to allow the cement slurries to infiltrate easily through unfilled compacted skeletons. A paired-sample t-test was carried out to find out whether water/cement ratio, SP percentages, and use of silica fume influence the cementitious grout performance. The findings showed that the replacement of …
Engineering Properties Of Oil Palm Shell Lightweight Concrete Containing Fly Ash, Hilmi Mahmud
Engineering Properties Of Oil Palm Shell Lightweight Concrete Containing Fly Ash, Hilmi Mahmud
Hilmi Mahmud
The effect of cement replacement with type F fly ash at 0%, 10%, 30% and 50% on some engineering properties of an oil palm shell (OPS) high strength lightweight concrete was investigated. The properties studied include workability, density, compressive strength, splitting tensile strength, flexural strength, water absorption and drying shrinkage. The effect of initial water curing periods of 2, 4 and 6. days after demoulding and air drying environment on the 28-day compressive strength was also investigated. The test results showed that even with 50% substitution of cement with fly ash, a low cost grade 30 OPS lightweight concrete can …
Oil Palm Shell Lightweight Concrete Containing High Volume Ground Granulated Blast Furnace Slag, Hilmi Mahmud
Oil Palm Shell Lightweight Concrete Containing High Volume Ground Granulated Blast Furnace Slag, Hilmi Mahmud
Hilmi Mahmud
With the ever-increasing industrialization and urbanization, huge amounts of natural resources are required to make concrete. Green concrete can provide a solution to reducing the negative impact of the concrete industry. This paper presents the results of experiments conducted to produce green structural lightweight concrete by using oil palm shell (OPS) as coarse aggregate, and ground granulated blast furnace slag (GGBFS) as a supplementary cementing material at 30%, 50% and 70% replacement of cement, and exposed to different curing conditions. Depending on the curing condition, test results show the possibility of producing green structural lightweight aggregate concrete with 28-day compressive …
Effect Of Magnesium Sulphate On Self-Compacting Concrete Containing Supplementary Cementitious Materials, Hilmi Mahmud
Effect Of Magnesium Sulphate On Self-Compacting Concrete Containing Supplementary Cementitious Materials, Hilmi Mahmud
Hilmi Mahmud
The length change is negligible and can be attributed to the normal distension of concrete. On the other hand, concrete suffering from mass loss gives a good indicator about the durability of SCC. Permeability of concrete is an important factor in classifying its durability generally; concrete with low Permeability will afford better protection of the reinforcement within it than concrete with high Permeability. In this paper, the assessment of magnesium sulphate (MS) attack on concrete containing various ratios of the supplementary cementitious materials (SCM) was investigated for concrete containing FA, RHA, and GGBS with cement replacement levels of 15%, 10%, …
Relationships Between Compressive Strength Of Cement-Slag Mortars Under Air And Water Curing Regimes, Hilmi Mahmud
Relationships Between Compressive Strength Of Cement-Slag Mortars Under Air And Water Curing Regimes, Hilmi Mahmud
Hilmi Mahmud
In this investigation 12 mortar mixes including three groups were prepared using binder contents 380 and 500 kg/m 3. All the specimens were cured after casting and demoulding in curing regimes, i.e. at room temperature (ac) and in water (wc). The highest strength was obtained for cement-slag mortars 380-wc at later ages as 80 MPa. For all groups of mortars, there could rarely be strength loss at later ages. It was observed that in duration of 3-7 days, wc is the optimum for all groups of mortars with exception of cement mortar 500 and slag mortar 500. In duration of …
Effect Of Replacement Of Normal Weight Coarse Aggregate With Oil Palm Shell On Properties Of Concrete, Hilmi Mahmud
Effect Of Replacement Of Normal Weight Coarse Aggregate With Oil Palm Shell On Properties Of Concrete, Hilmi Mahmud
Hilmi Mahmud
Oil palm shell (OPS) is a waste from the agricultural sector and is available in large quantities in the tropical regions. This paper investigates the effect of the replacement of normal weight coarse aggregate by oil palm shells on the compressive strength, density, modulus of elasticity, workability and water absorption. The gradation of substitution was 0, 28, 55, 83 and 100 %. Two mixes based on high strength concrete (HSC) with binder (cement + silica fume) content of 550 and 600 kg/m 3 were used. The results show that the compressive strength, density and modulus of elasticity decrease and workability …
Lightweight Concrete Made From Crushed Oil Palm Shell: Tensile Strength And Effect Of Initial Curing On Compressive Strength, Hilmi Mahmud
Lightweight Concrete Made From Crushed Oil Palm Shell: Tensile Strength And Effect Of Initial Curing On Compressive Strength, Hilmi Mahmud
Hilmi Mahmud
Oil palm shell (OPS) is a waste lightweight aggregate originating from the palm oil industry, which is approximately 50% lighter than conventional aggregate. In this study, crushed old OPS was used as coarse aggregate. Compressive strength under different curing conditions and the splitting tensile and flexural strengths were compared with those of the normal weight granite concrete. The test results showed that OPS concrete with a compressive strength in the range of 34-53 MPa has a splitting tensile strength range of 2.8-3.5 MPa and flexural strength range of 4.4-7.0 MPa. The sensitivity of compressive strength of OPS concrete in this …
Lightweight Aggregate Concrete Fiber Reinforcement - A Review, Hilmi Mahmud
Lightweight Aggregate Concrete Fiber Reinforcement - A Review, Hilmi Mahmud
Hilmi Mahmud
The higher brittleness and lower mechanical properties of lightweight aggregate concrete (LWAC) compared to normal weight concrete (NWC) at the same compressive strength has prevented it from being widely used in the construction industry despite its many advantages. Studies have shown that the use of fibers in LWAC is an appropriate solution to resolve such problems. This paper reviews the influence of the addition of fibers on the properties of different types of LWAC. These properties include the workability, compressive strength, stress-strain behavior, tensile strength, modulus of elasticity, and compressive and flexural toughness. Generally, the inclusion of fibers in LWAC, …
Effect Of Steel Fiber On The Mechanical Properties Of Oil Palm Shell Lightweight Concrete, Hilmi Mahmud
Effect Of Steel Fiber On The Mechanical Properties Of Oil Palm Shell Lightweight Concrete, Hilmi Mahmud
Hilmi Mahmud
This paper reports the results of a study conducted to investigate the effect of low volume content of steel fiber on the slump, density, compressive strength under different curing conditions, splitting tensile strength, flexural strength and modulus of elasticity of a grade 35 oil palm shell (OPS) lightweight concrete mixture. The results indicate that an increase in steel fiber decreased the workability and increased the density. All the mechanical properties except the modulus of elasticity (E) improved significantly. The 28. day compressive strength of steel fiber OPS lightweight concrete in continuously moist curing was in the range of 41-45. MPa. …
Oil Palm Shell As A Lightweight Aggregate For Production High Strength Lightweight Concrete, Hilmi Mahmud
Oil Palm Shell As A Lightweight Aggregate For Production High Strength Lightweight Concrete, Hilmi Mahmud
Hilmi Mahmud
In Malaysia, oil palm shell (OPS) is an agricultural solid waste originating from the palm oil industry. In this investigation old OPS was used for production of high strength lightweight concrete (HSLC). The density, air content, workability, cube compressive strength and water absorption were measured. The effect of five types of curing conditions on 28-day compressive strength was studied. The test results showed that by incorporating limestone powder and without it, it is possible to produce the OPS concretes with 28-day compressive strength of about 43-48 MPa and dry density of about 1870-1990 kg/m3. The compressive strength of OPS HSLC …
High-Strength Rice Husk Ash Concrete Incorporating Quarry Dust As A Partial Substitute For Sand, Hilmi Mahmud
High-Strength Rice Husk Ash Concrete Incorporating Quarry Dust As A Partial Substitute For Sand, Hilmi Mahmud
Hilmi Mahmud
Quarry dust is a by-product from the granite crushing process in quarrying activities. This paper presents the findings from experimental work undertaken to evaluate the suitability of quarry dust as a partial substitute for sand in high-strength concrete (HSC) containing rice husk ash (RHA). Two grades of HSC mixes, to achieve 60 MPa and 70 MPa at 28 days, were designed with and without the incorporation of RHA. Quarry dust was then used in the mixes containing RHA as a partial substitute for sand, in quantities ranging from 10% to 40%. The slump of the fresh concrete and the compressive …
Study On Properties Of Rice Husk Ash And Its Use As Cement Replacement Material, Hilmi Mahmud
Study On Properties Of Rice Husk Ash And Its Use As Cement Replacement Material, Hilmi Mahmud
Hilmi Mahmud
This paper investigates the properties of rice husk ash (RHA) produced by using a ferro-cement furnace. The effect of grinding on the particle size and the surface area was first investigated, then the XRD analysis was conducted to verify the presence of amorphous silica in the ash. Furthermore, the effect of RHA average particle size and percentage on concrete workability, fresh density, superplasticizer (SP) content and the compressive strength were also investigated. Although grinding RHA would reduce its average particle size (APS), it was not the main factor controlling the surface area and it is thus resulted from RHA's multilayered, …
Production Of High Strength Concrete Incorporating An Agricultural Waste- Rice Husk Ash, Hilmi Mahmud
Production Of High Strength Concrete Incorporating An Agricultural Waste- Rice Husk Ash, Hilmi Mahmud
Hilmi Mahmud
Rice husk which is an agricultural waste, constitutes about one-fifth of the 500 million tonnes of rice produced annually worldwide. Normally, the residue is disposed off by burning at the mill sites and the resultant rice husk ash (RHA) is dumped on a waste land. This generates environmental, pollution and land dereliction problems. Under controlled burning and if sufficiently ground, the highly reactive ash that is produced can be used as a supplementary cementing material or in the production of high strength concrete (HSC). This paper shows that it is relatively easy to produce high strength Grade 80 concrete incorporating …
Development Of Lightweight Concrete Using Industrial Waste Material, Palm Kernel Shell As Lightweight Aggregate And Its Properties, Hilmi Mahmud
Hilmi Mahmud
Agricultural industrial wastes produced after extracting palm oil from palm fruits known as palm kernel shell (PKS) are available in large quantities in Indonesia, Malaysia, Nigeria and other tropical countries. Malaysia is the second largest palm oil producing country in the world. This paper reports the results of an investigation conducted to utilize the PKS as lightweight aggregate to produce grade30 concrete with density of about 1850kg/m 3. The properties of both PKS and crushed granite aggregates were compared. The concrete produced using PKS referred to here after as palm kernel shell concrete (PKSC) and its properties were compared with …
Shear Strength Of Oil Palm Shell Foamed Concrete Beams, Hilmi Mahmud
Shear Strength Of Oil Palm Shell Foamed Concrete Beams, Hilmi Mahmud
Hilmi Mahmud
Four reinforced oil palm shell foamed concrete (OPSFC) beams were fabricated, and their shear behaviour was tested. The OPSFC has a target density of approximately 1600 kg/m3 and a 28-day compressive strength of about 20 MPa. Two beams were cast with shear reinforcements while the other two were cast without such reinforcements. For comparison, four reinforced normal weight concrete (NWC) beams were also cast. The beams that contained shear links failed in flexure mode, while those without links failed in shear mode. The experimental results indicated that the shear capacities of OPSFC beams without shear links are higher than those …
Chemical Stabilization Of Scrap Metal Yard Contaminated Soil Using Ordinary Portland Cement: Strength And Leachability Aspects, Hilmi Mahmud
Chemical Stabilization Of Scrap Metal Yard Contaminated Soil Using Ordinary Portland Cement: Strength And Leachability Aspects, Hilmi Mahmud
Hilmi Mahmud
In this study, the strength development and lechability aspects of metal-contaminated soil treated with ordinary portland cement (OPC) were investigated. The soil was collected from a scrap metal yard within the outskirts of Kuala Lumpur, Malaysia. Metal composition analysis indicated that the predominant metals present in the soil were iron (42,194 mg/kg), aluminium (8874 mg/kg), zinc (690 mg/kg), lead (428 mg/kg), copper (107 mg/kg) and chromium (52 mg/kg). The contaminated soil was treated with OPC using cement-to-dry soil (C/Sd) ratios of 0.5, 1 and 2. The effectiveness of the treatment was evaluated by performing unconfined compressive strength (UCS) as well …
Prediction Of Splitting Tensile Strength Of High-Performance Concrete, Hilmi Mahmud
Prediction Of Splitting Tensile Strength Of High-Performance Concrete, Hilmi Mahmud
Hilmi Mahmud
Splitting tensile strength (STS) is one of the concrete mechanical properties that are used in structural design. It can be related to numerous parameters, which include compressive strength, water/binder (W/B) ratio and concrete age. Until now, most researchers estimated the STS directly from compressive strength data. This paper suggests formulae that relate STS with that of compressive strength, W/B ratio and concrete age. The predicted STS can be obtained accurately using these formulae. It is proposed that the equation with the concrete age (t) parameter be used in predicting the STS of high-performance concrete (HPC). © 2002 Elsevier Science Ltd. …
Development Of High Performance Concrete Using Silica Fume At Relatively High Water-Binder Ratios, Hilmi Mahmud
Development Of High Performance Concrete Using Silica Fume At Relatively High Water-Binder Ratios, Hilmi Mahmud
Hilmi Mahmud
The aim of this study was to investigate the possibility of developing high performance concrete (HPC) using silica fume (SF) at relatively high water-binder ratios. For this purpose, water-binder ratios of 0.45 and 0.50 were considered. Test specimens were air and water cured and exposed to a medium temperature range of 20 °C to 50 °C. The compressive strength, modulus of elasticity and initial surface absorption (ISA) of hardened concrete were determined in the laboratory. Test results indicated that concrete under water curing offers the best results. The highest level of compressive strength and modulus of elasticity and the lowest …