Ahmad Ruslan Mohd Ridzuan

Strength assessment of controlled low strength materials (CLSM) utilizing recycled concrete aggregate and waste paper sludge ash

This paper studies the strength development of low-strength material (CLSM) is controlled by using waste paper sludge ash (WPSA) in CLSM mixtures without adding Portland cement. Series of four (4) compounds which is the CLSM containing 5%, 10%, 20% and 30% of waste paper sludge ash (WPSA) as a substitute for Portland cement. CLSM cubes the sizes of 100mm × 100mm × 100mm compressive strength were tested at age 7, 14 and 28days. It was found that this activity contributes to strength development pozzolonic paper waste sludge ash (WPSA) depending on the percentage of the added waste paper sludge ash. So, it was found that the activity pozzolonic has been activated by the alkaline and calcium hydroxide (Ca(OH)2) contributed from recycled concrete aggregate (RCA). In this study, the alkaline releases when soaked in water for 28days. Compressive strength of controlled low-strength materials affected by both the ratio of fine aggregate and coarse aggregate and mixture characteristics during maturation developed CLSM. Cube test results show that CLSM with a ratio of 1∶2 and 1∶1 RCA and 20mm recycled coarse aggregate, 30% of WPSA content expressed as mass percentage of RCA is to produce a uniform mixture with a constant high-strength (maximum strength of 6.04MPa).

The evaluation of self consolidating concrete incorporating crushed concrete waste aggregate

Self consolidating concrete (SCC) is an innovative concrete that does not require vibration for placing and compaction. It offers a rapid rate of concrete placement, with faster construction times and ease of flow around congested reinforcement. The improved construction practice and performance, combined with the health and safety benefits, make SCC a very attractive solution for both precast concrete and civil engineering construction [1]. If the production of concrete wastes is not managed properly, Malaysia will face major environmental problems. The Government will have to bear the unnecessary costs for clean-ups, repairs and protection measures on illegal dumping areas and providing more landfills. Recycling of waste concrete as crushed concrete waste aggregate (CCWA) for new concrete is beneficial for environmental preservation and effective utilization of resources. This study is to determine the compressive strength performance of SCC using CCWA as coarse aggregate with various replacement percentages of 0%, 25%, 50%, 75% and 100% of CCWA to normal aggregate for grade 30 N/mm2 concrete. The specimens were tested for compressive strength at 3, 7, 14 and 28 days age. Results indicated that the compressive strength of SCC containing up to 25% CCWA coarse aggregate replacement is comparable to the compressive strength of normal aggregate SCC.

Alkaline Activators Concentration Effect to Strength of Waste Paper Sludge Ash- Based Geopolymer Mortar

The purpose of this study is to determine the effect of concentration of sodium hydroxide solution on the strength of Waste Paper Sludge Ash (WPSA)-based geopolymer mortar. Initially, the WPSA samples were been analyzed using X-ray Fluorescence (XRF) to determine the chemical composition. From the XRF analysis, the by-product WPSA manufactured from Malaysian Newsprint Industry (MNI), located at Mentakab Pahang, Malaysia containing higher amount of calcium, silica and alumina. Alkaline solution are from soluble sodium-based used in geopolymerization are combination of Sodium Hydroxide (NaOH) and Sodium Silicate (Na2SiO3). The specimens were carried out on size 50 × 50 × 50 mm cube and fresh mortar were been cured at an oven temperature and ambient temperature. The compressive strength tests were conducted after aging the specimen at 3, 7, 14, and 28 days. The results revealed that as the concentration of NaOH increased, the compressive strength of geopolymer mortar increases. However, the optimum NaOH concentration of WPSA geopolymer mortar is at 12 M. More than 12 M concentrations of NaOH were produced high porosity and decreasing the strength. The range of Na2SiO3 to NaOH solution ratio by mass to produce high strength geopolymer mortar is 2.5. Moreover, curing of fresh WPSA geopolymer mortar is performed mostly at an oven temperature compared to ambient temperature due to heat being a reaction accelerator.

The quantification of local construction waste for the current construction waste management practices: A case study in Klang Valley

Throughout the years, the construction industry plays a significant role in helping the nation to achieve the main goal of sustainable development in the lives of society in Malaysia. With the demands of major residential housing project developments, it shows that the construction sector is being expanded and developed. Moreover, it has been observed that the construction waste is one of the priority waste streams. Due to the increasing population that is actively involved in economic activities and the modernisation of the country, the types of construction wastes that is being produced is becoming more complex and has yet to be identified. Therefore, the established system to record quantitative data for the generation of construction waste has yet to be formally standardized and is still lacking across much of Asian and developing countries. To address this need, the study on the types and composition of construction waste generated is carried out as a logical first step towards assisting the construction waste management through the categorization of construction waste in Klang Valley. Throughout this study, useful information concerning waste assessment data is necessary to achieve a better understanding of construction waste obtained. Case studies involving quantification and classification of construction waste for several on-going residential housing developments in Klang Valley, Malaysia have been presented. This paper concludes with the identification of database information concerning the quantification of local construction waste which was developed for the current practices of construction waste management.

Estimation model of construction waste materials in Malaysia: Steel

Nowadays, construction waste issues have become a major concerned in most countries to both practitioners and researchers towards a sustainable development. In Malaysia, awareness on the documentation of construction waste generated from construction activities is still lacking although such record may offer a better waste management system. Meanwhile, various models in quantifying the construction waste materials have been developed in many countries to improve the management of construction waste. Quantification model on construction waste has been described as an important element to be considered for a better waste management. Therefore, this paper intends to provide a mechanism to predict the amount of construction waste for steel generated from a building project. Reviews from previous studies on construction waste quantification and management was done to identify the variables contributed to the construction waste generation. Besides, archival documents comprised of taking off, delivery order and as built drawings of the residential projects were collected from contractors. The findings of this research resulted the adjusted R-square value 0.833 and the performances of the modes was evaluated by using the mean absolute percentage error (MAPE). The value is 23.836% and was categorized as common for range 20-50%.

Supply Chain Management on IBS Implementation in Klang Valley Construction Industry: Challenges and Issues

Industrialized Building System (IBS) is a system where the components of the building are manufactured in a factory and it will be transported to the site to form the structures. The supply chain management (SCM) is a system where the delivery flows of the IBS products from manufacturers to the site. The aim of this research is to identify the major challenges and to analyze the issues on IBS implementation in SCM in Klang Valley from the manufacturers perspective. The methodology used in this paper is based on primary data through questionnaire and interview. Questionnaires were sent to the Manufacturers. It can be concluded that this paper attempts to present more on the challenges and issues that those companies of manufacturers faced during their success journey in finding integration in their supply chain. The main contributions of this paper are integrating all the supply chain integration challenges and issues on IBS. Therefore, these contributions will be helpful for the organization of manufacturers and IBS players that establish the integration in their SCM.

Effect of alkaline activators concentration to the strength and morphological properties of wastepaper-based geopolymer mortars

Waste paper sludge ash (WPSA) is a byproduct that has potential to replace Ordinary Portland Cement (OPC) as a building material. The purpose of this study is to investigate the effect of NaOH concentration on the strength of Waste Paper Sludge Ash (WPSA)-based geopolymer mortar. Initially, the WPSA samples were been analyzed using X-ray Fluorescence (XRF) to determine the chemical composition. From the XRF analysis, the by-product WPSA containing higher amount of calcium, silica and alumina. Alkaline solution are from soluble sodium-based used in geopolymerization are combination of Sodium Hydroxide (NaOH) and Sodium Silicate (Na2SiO3). The mortars samples were cast with various concentration of NaOH and ratio of Na2SiO3 /NaOH which is 2.5. The specimens were carried out on size 50x50x50 mm cube and fresh mortar were been cured at 70 ̊c oven temperature and ambient temperature. The compressive strength tests were conducted after aging the specimen at 3, 7, 14, and 28 days. The results revealed that as the concentration of NaOH increased, the compressive strength of geopolymer mortar increases. However, the optimum NaOH concentration of geopolymer mortar is at 12M. More than 12M concentrations of NaOH were produced high porosity and decreasing the strength. Moreover, curing of fresh geopolymer mortar is performed mostly at an oven temperature compared to ambient temperature due to heat being a reaction accelerator. This paper also present on the morphology, and Energy dispersive x-Ray (EDX) composition analysis of WPSA based geopolymer mortar.

The Effect of NaOH Concentration and Curing Condition to the Strength and Shrinkage Performance of Recycled Geopolymer Concrete

Concrete is widely used as a material construction. Globally, the consumption of concrete was estimated to be more than 8 billion tons per year. Nowadays, many problems arise related to concrete manufacturing occur especially on environmental issues. A key concern for environmentalists has always been climate change. One of the ways to mitigate the impact activities on the climate is to reduce carbon footprint. Portland cement are commonly been used in concrete is responsible for about 5% of all CO2 emission. It is reported by Davidovit that the production of one ton of Portland cement emits approximately one ton of CO2 into the atmosphere. There are several ways to reduce environmental pollution that cause by production and utilization of Portland cement, one of it is Geopolymer concrete. Subsequently Geopolymer concrete incorporating with recycle concrete aggregate (RCA) is one of the alternative to further reduce carbon footprint and as well as can reduce waste. Geopolymer concrete is a concrete that use no cement and produced by the combination of alkaline activator and supplementary cementitious material (SCM) such as fly ash, boiler ash, waste paper sludge ash (WPSA), ground granulated blast-furnace slag (GGBS), and so on in order to reduce carbon emission. In this study the Waste Paper Sludge Ash (WPSA) were used as a SCM and the combination of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) as a binder. Two (2) series of geopolymer concrete specimens comprising two (2) different molar of sodium hydroxide (NaOH) which are 8M and 14M were adopted. The effect variable alkaline molarity on the compressive strength and shrinkage of the geopolymer concrete specimens is tested at the age of 3, 7, 14 and 28 days. The mixture of geopolymer concete with 8M of sodium hydroxide (NaOH) concentration then was categorized into three (3) groups. Each group were been cured at different curing condition which are in ambient condition, oven, and external condition. The size of specimens prepared were 100mm x 100mm x100mm. The result shows that the molarities of sodium hydroxide (NaOH) influenced the strength of Waste Paper Sludge Ash (WPSA) based geopolymer concrete produced incorporating with increasing of recycle concrete aggregate (RCA). The result also show that the geopolymer concrete undergoes very low shrinkage. Curing condition will also effect the strength of geopolymer concrete produced.

Morphology and Physical Analysis of Waste Paper Sludge Ash (WPSA) Polymeric Mortar

Waste paper sludge ash (WPSA) is a byproduct and problematic waste of paper industries. The investigation was driven by the increasing demand for reuse options in paper-recycling industry. This paper present on the morphology and physical analysis studies on polymerization of WPSA mortar. Two (2) types of polymeric mortar mixes containing WPSA with alkaline activators and without alkaline activators were prepared. The morphology of each mixes was determined using Spectra Electron Microscope (SEM) and the physical test is focus on compressive strength. However, the element diffraction of each mixes using Energy Dispersive X-Ray Spectroscopy (EDX) was also carried out as a method to identify the polymerization of polymeric mortar. From the result obtained it is found that the utilization of WPSA reduced the polymerization of polymeric mortar due to more pores. From the EDX analysis it is also revealed that the WPSA polymeric mortar also contained less synthetic aluminous silicate compound. However, the strength gain up to 6MPa and it is comparable with other high calcium material mortar.

Effect of Limestone Powder in Self Consolidating Lightweight Foam Concrete

Self-Consolidating Lightweight Foam Concrete (SCLFC) is known as a concrete which has no requirement towards vibration or compaction effort due to its flowability and capability in filling and achieving full compaction in reinforcement. The main component in SCLFC is cement. Cement is a basic component of concrete that used in construction industry. However, it is also the main source of Carbon Dioxide (CO2) emission. If this component of concrete is replaced with other materials, it surely can help in reducing the emission of CO2. Limestone powder can be replacement with the cement content in SCLFC. Therefore, the aim of this paper is to determine the effect of limestone powder on SCLFC in term of flowability and compressive strength. The specimens were tested for compressive strength at 3, 7, and 28 days. The result indicated the flowability of SCLFC increase with the increase of percentages of limestone powder replacement. Meanwhile, the highest compressive strength of SCLFC containing 10% limestone powder replacement give better performance than the normal SCLFC. Based on the finding, SCLFC containing 10% limestone powder replacement can be categorized same as a conventional concrete hence it can be utilized for construction purposes. Limestone powder can also acts as an alternative replacement in concrete for replacing the cement.