Norwati Jamaluddin

The Effect of Bottom Ash on Fresh Characteristic, Compressive Strength and Water Absorption of Self-Compacting Concrete

Bottom ash is a solid residue produced through combustion process in a coal-fired power plant. It has been catogarized as a waste and usually disposed in the utility disposed site. With higher demand on the power energy, more coal-power plant are constructed and abundance of bottom ash are produced. Recently, the utilization of bottom ash in the construction industry has gained the interest of researches. Since it has similiar particle size distribution as normal sand, many attempt has been made in studying it potential use in mortar and concrete. In complementary to that, this paper presents the effect of bottom ash on fresh and hardened properties of self-compacting concrete (SCC). Bottom ash is used as fine aggregate replacing sand with replacement ratio range from 0% to 30% by volume. The effects of bottom ash on the SCC were investigated by comparing the test result of SCC mixed bottom ash with control specimens (0% of bottom ash). The test result on fresh properties of the concrete mixture revealed that, as the replacement level of bottom ash increased, the slump flow, L-box passing ratio and segregation resistance ratio (SR) decreased. Nevertheless, the slump flow time (T500) result increased with the increased of bottom ash content. The results show that the porosity and the irregular shape of the bottom ash particle has great influence on workability and viscosity of the fresh concete. The compressive strength and water absorption test are carried out on the sample at curing time of 7 and 28days. In terms of strength, the use of bottom ash in the production of SCC has increased the compressive strength of the concrete up to 15% replacement level. The increase in strength show the presence of the pozzolanic reactivity in a concrete with bottom ash particle. The water absorption rate was observed to be lower with a sample which having 10% and 15% replacement level.

Compressive and flexural strength of foamed concrete containing polyolefin fibers

Foam concrete is a lightweight concrete which is produced relatively inexpensively. However, due to its low strength and brittleness the application in building construction is rather limited. A study has been undertaken to investigate the effects of polyolefin fibers at a relatively low volume fraction (0 %, 0.2 %, 0.4 % and 0.6 %) on the compressive and flexural properties of foamed concrete. The foamed concrete was designed to achieve a target strength of 8-10 MPa with a density of 1600 kg/m3 at the age of 28 days. For each mixture, nine 100x100x100 mm cubes and three 100x100x500 mm beam were prepared. The compressive test was performed on cubes and three points loading flexural test on the beams was carried out in accordance to MS 26:Part 2:1991. Test results showed that polyolefin fibers only slightly improved the compressive strength and flexural strength of foamed concrete by 4.3% and 9.3% respectively.

The Strength Behavior of Self-Compacting Concrete Incorporating Bottom Ash as Partial Replacement to Fine Aggregate

Self-compacting concrete which commonly abbrevited as SCC is a special concrete that have the ability to consilodate fully under its own self-weight without any internal or external vibration. This paper presents the experimental investigation carried out to study the strength of self-compacting concrete incorporating bottom ash at different replacement level of natural sand. The composite cement was used and the replacement level of bottom ash to natural sand is set up to 30% by volume. The strength properties such as compressive strength, split tensile strength and flexural strength of the concrete at the age of 7 and 28 days of curing day were conducted. Results shows that the strength of the concrete with bottom ash increased up to replacement level 15% higher than control specimens. This show that bottom ash can be used as supplimentary cementitious materials, having the pozzolanic reactivty.

Utilization of sugarcane bagasse ash in concrete as partial replacement of cement

This research addresses the suitability of sugarcane bagasse ash (SCBA) in concrete used as partial cement replacement. Two grades of concrete M15 and M20 were used for the experimental analysis. The cement was partially replaced by SCBA at 0%, 5%, and 10%, by weight in normal strength concrete (NSC). The innovative part of this study is to consider two grades of concrete mixes to evaluate the performance of concrete while cement is replaced by sugarcane bagasse ash. The cylindrical specimens having size 150 mm × 300 mm were used and tested after curing period of 7, 14 and 28 days. It was observed through the experimental work that the compressive strength increases with incorporating SCBA in concrete. Results indicated that the use of SCBA in concrete (M20) at 5% increased the average amount of compressive strength by 12% as compared to the normal strength concrete. The outcome of this work indicates that maximum strength of concrete could be attained at 5% replacement of cement with SCBA. Furthermore, the SCBA also gives compatible slump values which increase the workability of concrete.

Ultimate strength capacity of a square hollow section filled with fibrous foamed concrete

Concrete-filled sections used as building columns have become popular due to their architectural and structural elements. In recent years, there has been a renewed call for the improvement of materials used as concrete to fill the composite columns. Among these materials, foamed concrete has received great attention due to its structural characteristics and its potential as a construction material used in hollow sections. However, its behaviors as infill material in a hollow section, such as its strength and failure mode, should be investigated. In this study, experimental research was conducted to compare the experimental and theoretical values of its ultimate strength capacity. Eight specimens of hollow steel sections with two different thicknesses were filled with fibrous foamed concrete and then subjected to compression load. The obtained results were compared with those obtained from a hollow section with the same thicknesses, but were filled with normal foamed concrete. Results show that the ultimate strength capacity of the experimental value is the same as that of the theoretical value based on Eurocode 4. The largest percentage values between theoretical and experimental results for thicknesses of 2 and 4 mm are 58% and 55%, respectively.

Strength of Reinforced Fibrous Foamed Concrete-Filled Hollow Section

At present, research on concrete-filled sections extends to using lightweight concrete to reduce the total weight of such structures. However, research on concrete-filled hollow sections (CFHS) using foamed concrete remains ongoing. Therefore, this study was conducted to determine the strength of reinforced fibrous foamed CFHSs. Two types of fibre, namely, steel and polypropylene fibres, were used. A short-column specimen was prepared and tested under compression load. Result shows that adding steel fibre to foamed concrete indicates a higher strength than adding polypropylene fibre. The strength of the CFHS is increased by adding reinforced bar and fibre in foamed concrete.

Precast self-compacting concrete (PSCC) panel with added coir fiber: An overview

Self-compacting concrete (SCC) is the alternative way to reduce construction time and improve the quality and strength of concrete. The panel system fabricated from SCC contribute to the IBS system that is sustainable and environmental friendly. The precast self-compacting concrete (PSCC) panel with added coir fiber will be overview in this paper. The properties of SCC and coir fiber are studied and reviewed from the previous researches. Finite element analysis is used to support the experimental results by conduction parametric simulation study on PSCC under flexure load. In general, it was found that coir fiber has a significant influence on the flexural load and crack propagation. Higher fiber incorporated in SCC resulted with higher ultimate load of PSCC.

Properties and Leachability of Self-Compacting Concrete Incorporated with Fly Ash and Bottom Ash

The process of combustion in coal-fired power plant generates ashes, namely fly ash and bottom ash. Besides, coal ash produced from coal combustion contains heavy metals within their compositions. These metals are toxic to the environment as well as to human health. Fortunately, treatment methods are available for these ashes, and the use of fly ash and bottom ash in the concrete mix is one of the few. Therefore, an experimental program was carried out to study the properties and determine the leachability of selfcompacting concrete incorporated with fly ash and bottom ash. For experimental study, self-compacting concrete was produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a replacement for sand with the ratios of 10%, 20%, and 30% respectively. The fresh properties tests conducted were slump flow, t500, sieve segregation and J-ring. Meanwhile for the hardened properties, density, compressive strength and water absorption test were performed. The samples were then crushed to be extracted using Toxicity Characteristic Leaching Procedure and heavy metals content within the samples were identified accordingly using Atomic Absorption Spectrometry. The results demonstrated that both fresh and hardened properties were qualified to categorize as self-compacting concrete. Improvements in compressive strength were observed, and densities for all the samples were identified as a normal weight concrete with ranges between 2000 kg/m3 to 2600 kg/m3. Other than that, it was found that incorporation up to 30% of the ashes was safe as the leached heavy metals concentration did not exceed the regulatory levels, except for arsenic. In conclusion, this study will serve as a reference which suggests that fly ash and bottom ash are widely applicable in concrete technology, and its incorporation in self-compacting concrete constitutes a potential means of adding value to appropriate mix and design.

Performance of Recycled Aggregate Containing POFA as Additives for Cement

Malaysia has been the largest producer and exporter of palm oil in the world, accounting for 52% of the total world oil in year 2006. The waste disposal problem from palm oil industry was increasing. In addition, the government also facing the problems when forced to allocate more landfill for the disposal of concrete waste. Nowadays, the by-product the palm oil mill has becoming potentially to be utilized as construction material in term as additives for cement. This paper discussed the water absorption and compressive strength of Recycled Aggregate Concrete (RAC) containing Palm Oil Fuel Ash (POFA). There are twelve (12) series of concrete mix containing POFA and recycled aggregate (RA) were used as additives for cement that have been indicated as POFA-0%, POFA-10%, POFA-20%, POFA-30% and RA-0%, RA-50% and RA-100%. The slump test was conducted to determine the performance of fresh concrete. The hardened concrete have been tested its compressive strength and water absorption of POFA-concretes at 7 and28 days of water curing ages. The results revealed that POFA-recycled aggregate concrete has lower water absorption and higher compressive strength comparedto recycled aggregate concrete without POFA. The optimum additional of POFA was 30% for concrete made with 100% natural aggregate (NA) produced higher compressive strength and lower water absorption.

Experimental Tests on Composite Beam with Various Slab Systems

This paper presents the structural behaviour of composite beams with various floor systems tested in full-scale arrangement. Six full-scale specimens with staggered and non-staggered arrangement of studs on the composite beams were tested until failure. The moment capacities obtained from the experiment are compared with the theoretical values established from BS 5950 and Eurocode 4. The experimental results showed good agreement with theoretical predictions while no significant influences were found between staggered and non-staggered arrangement of studs.