Fadhluhartini Muftah

Properties of Waste Paper Sludge Ash (WPSA) as cement replacement in mortar to support green technology material

Waste Paper Sludge Ash (WPSA) is a waste material collected from the Paper Industry. WPSA is used as cement replacement in producing mortar and was investigated on its chemical, physical and mechanical properties. Construction material with natural resources now become limited and causes of air pollution and environmental problems. WPSA becomes a new innovation material that can be used as material for masonry to support the green technology due to less presence of sulphate at only 0.57% of the total weight. Carbon dioxide (CO2) and Sulphur dioxide emission also can be reduced since less cement productivity is involved. The chemical and physical properties of the WPSA were determined by comparing it with the Ordinary Portland Cement (OPC). As the result of testing, it shows that WPSA is similar to the chemical properties of OPC and the water absorption of the mortar is 27.05%. However the total percentage of the three combinations of SiO2, Al2O3 and Fe2O3 was 45% and expected to possess low pozzolanic reactivity (50%). WPSA was used in mortar with proportions of 50%, 60%, 70%, 80%, 90% and 100% as cement replacement by volume along with sand and water in fix quantity. An additional control mix mortar without WPSA was also prepared. The compressive strength of each mortar mix was also determined on 3, 7, 28 and 60 days. Results show that the compressive strength increased with increasing curing age for all concrete mixes and the compressive strength decreases with increasing WPSA in the mortar. The inclusion of 50% WPSA can gain favorable strength mortar at 16.4 MPa. Meanwhile 70% and 100% replacement can be adopted for economical environmental mortar to suit lower strength mortar construction at 12.5 MPa and 7.7 MPa respectively.

Comparison study of Bottom Ash Aggregate and Washed Bottom Ash Aggregate in concrete: Physical aspect

This paper presents the comparison physical study of solid waste of Bottom Ash Aggregate (BAA) and Washed Bottom Ash Aggregate (WBAA) as fine aggregate in concrete. The BAA is a waste material that is taken from electric coal power plant and the basic source material of WBAA is a treated bottom ash. The BAA is fully submerged in clean and clear water for 3 days to produce a WBAA with low amount of carbon. This WBAA with low carbon composition is utilised to produce concrete with less percentage of carbon usage. Low amount of carbon can reduce energy in building, reduce environmental impact and can be supported to green material in concrete. So that, this two types of bottom ash were studied their physical properties and then compared. The aim of the study is to investigate the physical comparison of BAA and WBAA in producing concrete or concrete applications. The results of the sieve analysis and fineness modulus of BAA and WBAA were discussed. The calculated of fineness modulus of BAA and WBAA are 4.93 and 3.65 respectively, which are more than 3.5 and it is considered very coarse. Finally, it is concluded that this both aggregate is potential for utilise in concrete and mortar or concrete/mortar application.

Experimental Investigation of Cold-formed Steel (CFS) Channel Material at Post Elevated Temperature

Cold formed steel (CFS) is the popular structural material used in the building nowadays due to a variety of advantages in its manufacturing, fabrication and erection. The main objective of the study is to study the properties of the CFS at post elevated temperature. When this material is exposed to fire the steel material properties are degraded. Therefore, it is important to predict the degradation of material properties of CFS after exposed to elevated temperatures. The microstructure test was found that after exposing to 1,000 °C temperature compared to normal CFS, the composition of eight elements in CFS has increased as Carbon, C is the highest at 129.7 %, meanwhile, thirteen elements are decreasing as Silicon, Si is the highest at 80.6 %. Results from tensile coupon test of post elevated temperature CFS shows that the cold formed steel that expose to fire may regain its yield strength within 10–60 % for range temperature 400–1,000 °C when compared to the Class 4 steel in EC3-1-2. The pattern of the reduction factor of CFS is similar to the hot rolled steel S460.

Effect of drying method on compressive strength of special concrete with bottom ash

From the electric coal power plant, the waste material that formed is the bottom ash and fly ash. Bottom ash is collected at the bottom of boiler or furnace and sometimes it is placed on the surface of the chamber in a water-filled hopper. High-pressure water is used to remove the bottom ash from the chamber. While, fly ash is disposed to atmosphere by tall chimney. 80% of product of electric coal power plant will become fly ash and remain 20% of product is bottom ash. The bottom ash is physically coarse, porous, light, glassy, granular, greyish and incombustible material that suitable used in concrete for civil engineering application. The type and properties of bottom ash produced depends on the type of boiler or furnace and also the sources of raw coal. With the chemical analysis and physical testing, the bottom ash show unique properties that can be applied in concrete. The study involved the high capacity oven and normal equipment for testing of concrete. The special concrete was produced by using bottom ash as sand replacement and checked their compressive strength. The compressive strength value is taken from the normal temperature and other exposed to 200°C. The concrete that been drying at 200°C were found as the superior in compressive strength followed by normal cure and drying for 100°C. This shows high temperature drying may produce higher early compressive strength.

Assessment on compressive strength of Waste Rubber Tube Tyre (WRTT) fiber in concrete

The study is concentrated on assessment on compressive strength of Waste Rubber Tube Tyre (WRTT) fiber as reinforced bar replacement in concrete. WRTT fiber is produced from waste tyre industry. WRTT fiber is determined for its density and percentage of water absorption. WRTT fiber is designed and cut to a size of 5 cm in length, 0.5cm in breadth and 0.1 cm in thickness. WRTT fiber is mixed with concrete with percentage proportion of 0%, 1%, 1.5%, 2.0% and 2.5%. All concrete are cured in clean and clear water and tested for compressive strength at 7 and 28 days. Every mixes illustrateda low compressive strength compared to a control mix. The highest percentage proportion of 1.0 % showed 40-45% different when compared with control mix for early and matured ages. Finally, further studies can be done to assess the general issues of strength to show the potential of WRTT fiber in concrete.

Preliminary Study of Compressive Strength of Concrete Incorporated with Waste Paper Fibres

Concrete incorporated with waste paper fibres (WPF) was studied to get the initial information of compressive strength before doing further action to solve a critical problem. Problems such as environmental problem, high production cost and concrete distress were solved to minimise the critical problem. The main objective of the preliminary study is to investigate the compressive strength of concrete with WPF at an appropriate percentage. Some review assessments from previous studies, either on industrial fibres or natural fibres with critics, were done to obtain information and upgrade knowledge. The compressive strength and water absorption result were reported for concrete without and with WPF in proportion of 0.2%, 0.4%, 0.6%, 0.8%, 1.0% and 1.5%. From the observation and testing, the compressive strength of concrete with WPF was decreased with increase in fibre percentage in the concrete. Besides, the water absorption, which always influence the compressive strength, was increased when the percentage of fibres increased; thus, some recommendations and adjustments are proposed for the next feat to produce waste paper fibre concrete with better compressive strength and greater water absorption, and thus solve the environmental issues and enable waste material to support sustainable materials in construction and building.

Experimental investigation on box-up cold-formed steel columns in fire

Cold-formed steel is a popular material with various advantages. Its easy production and assembly give engineer an option to speed the construction process. However, thinness relates to the major issue of buckling, especially when dealing with high temperature. The unprotected cold-formed steel behaviour under fire is expected to have a little strength as compared to hot-rolled steel. Information on such behaviour is still limited. Fire resistance testing on built-up box CFS column was presented in this paper. Two fire resistance tests were carried out under compression load. The Standard ISO 834 Fire Resistance Test under 50% and 70% degree of utilisation measured the temperatures at several points of the steel column surface by using a surface thermocouple and axial column deformation. For reference purpose, one same static test at ambient temperature was carried out to assess the load bearing capacity. Results found that the failure temperature of built-up CFS could reach up to 515 °C and 443 °C within 8 minutes and 7 minutes resistant time for 50 % and 70% degree of utilisation, respectively. Based on deformation analysis, buckling temperature of the column was 448 °C and 394 °C with a critical time of 7 minutes for 50 % and 70% degree of utilisation, respectively. This concluded that the higher degree of utilisation results in lower critical temperatures of the columns.

Tension Behaviour on the Connection of the Cold-Formed Cut-Curved Steel Channel Section

Cold-formed steel (CFS) are utilised as a non-structural and structural element in construction activity especially a residential house and small building roof truss system. CFS with a lot of advantages and some of disadvantages such as buckling that must be prevented for roof truss production are being studied equally. CFS was used as a top chord of the roof truss system which normally a slender section is dramatically influenced to buckling failure and instability of the structure. So, the curved section is produced for a top chord for solving the compression member of the roof truss. Besides, there are lacked of design and production information about the CFS curved channel section. In the study, the CFS is bent by using a cut-curved method because of ease of production, without the use of skilled labour and high cost machine. The tension behaviour of the strengthening method of cut-curved or could be recognised as a connection of the cut-curved section was tested and analysed. There are seven types of connection was selected. From the testing and observation, it is shown the specimen with full weld along the cut section and adds with flange element plate with two self-drilling screws (F7A) was noted to have a higher value of ultimate load. Finally, there are three alternative methods of connection for CFS cut-curved that could be a reference for a contractor and further design.

Evaluation of Material Properties of Cold-formed Steel Channel Section with Different Thickness

Cold-formed steel channel (CFSC) section is a popular material that used broadly in construction, especially in the roof truss system and non-structural elements. CFSC with a variety of sizes, shapes, thicknesses and grades is becoming admired because it offers several advantages such as lightweight, easy fabrication, fast installation, no formwork, termite resistance and corrosion resistance. The main objective of the study is to investigate the CFSC material properties with a variety of thicknesses. When the CFSC is utilised as in construction structural material, the CFSC material properties must be evaluated for further work, especially in design, failure capacity information and modelling intention. The thickness of the CFSC is important in study to check the failure mode and mechanical properties of the material. The material properties of CFSC are examined by using tensile coupon test specimens and universal tensile testing machine. The CFSC that be used in the study is CFSC 1.0 and CFSC 1.2 with the thickness of 1.0 and 1.2 mm respectively for grade G450. The CFSC is selected by having intermediate end stiffener and lipped. The specimen of tensile coupon test is located on flange, web, upper corner and bottom corner of overall section. From the results, the yield stress, elastic modulus and ultimate stress of the CFSC 1.2 is found higher than of CFSC 1.0.

Assessment of Mechanical Properties of Cold Formed Steel Material at Elevated Temperature

Fire accident is considered as the one of most severe environmental hazards to building and infrastructure. Cold formed steel (CFS) beam has been used extensively as primary load bearing structural member in many applications in the building construction due to high efficiency in term of production, fabrication, and assembling in construction. This material must be well perform in fire incident in term of its integrity and stability of structural for a period of time. Hence, the assessment of the material properties of this material is greatly important in order to predict the performance of this structure under fire incident. The tensile coupon tests of CFS are according to BS EN 10002-1:2001. The CFS material G450 with 1.9 mm thickness is used in this study. The elastic modulus, yield stress, correspondent percentage strain at yield stress, ultimate stress, and correspondent percentage strain of ultimate stress was 200.3 GPa, 540.5 MPa, 0.478 %, 618.8 MPa, and 8.701 % respectively. The results of the ambient temperature test have been used to assess the mechanical strength of CFS at elevated temperature. The discussion of material properties is based on EC3-1-2 and proposed model from other researchers. The main material properties discussed is the stress-strain curve, elastic modulus, yield strength at elevated temperature was determined. The actual elastic region is slightly lower than the prediction of EC3-1.2 at ambient temperature, but well fit with two other studies. Besides that, the actual material properties experience strain hardening after yielding and reach a maximum stress up to 618 MPa while EC3-1.2 predict the constant value of the yield stress after yield until 15 % strain,other two study was fit the ambient tensile test up to ultimate stress, and fit until 2 % strain level.