Mechanical properties of rice husk ash as a mineral addition in concrete / Kartini Kamaruddin and Hamidah Mohd Saman

It is shown that some of the wastes have properties that would improve the quality of concrete produced. One such waste is agricultural waste rice husk, which constitutes about one-fifth of 600 million tones of rice produced annually in the world. The performance of RHA concrete was found to be varied among those of researchers and most of the studies encompassed for the utilisation of high grade concrete. This paper reported the investigation carried out on the mechanical properties of normal strength concrete of grade 30 N/mm2 with various partial replacement level of ordinary Portland cement (OPC) with Rice Husk Ash (RHA). Two(2) batches of same grade of concrete with and without use of superplasticiser (Sp) were adopted. The mechanical properties evaluated are in terms of compressive strength, flexural strength and tensile splitting strength of RHA concrete with and without superplasticiser (Sp). The results show that the optimum replacement level of RHA was 20 % and with the addition of Sp the replacement of RHA was taken as 40 %. However, the results of the study show that the performance in term of flexural strength and tensile splitting strength does not significantly improved with the replacement of cement with RHA

Optimisation of calcium silicate and sand cement bricks in masonary bearing walls / Kartini Kamaruddin and Siti Hawa Hamzah

Design and construction of buildings used to be on framed structure incorporating reinforced concrete, steel or timber as structural member to transmit load to the foundation. Bricks are normally used as infill materials in these framed structures. However, research has shown that bricks can also be used as external and internal masonry bearing walls. With the use of structural masonry construction method, cheaper and faster construction can be achieved. Savings are obtained by using less formwork and reinforcing steel, reducing construction time as lesser frames or none are used, and eliminating waiting time for the structural concrete to cure or gain their strength. Calcium silicate and sand cement bricks were tested for their mechanical properties. Investigations were carried out on six masonry bearing walls. Each unit measured 1000 mm × 1000 mm and a half brick thick. The structural behaviour due to compressive axial load was investigated and it shows that both bricks satisfy the requirement as load bearing wall. However, the study concluded that sand cement brick wall showed better performance, with maximum lateral displacement of 3.81mm, vertical deflection of 6.63 mm and ultimate load of 448.13 kN

The combined effects of Polyethylene Terephthalate and rubber crumb as fine aggregate in concrete / Norhana Abdul Rahman

Currently, the need to incorporate recycled materials such as plastics and rubbers as replacements to raw materials is becoming more important than ever before. In this study, the combined effects of Polyethylene Terephthalate (PET) and rubber crumb (RC) as fine aggregate replacement in concrete are investigated. This study evaluated the mechanical (compressive strength and flexural strength) and durability properties (electrical resistivity and water absorption) of the concrete. The fine aggregate was replaced at 10%, 20% and 30% by weight of binder and tested for 7, 28, 60 and 90 days of curing. The results showed that by increasing the replacement of PET in higher proportion (up to 20%) and RC (up to 10%) the compressive strength of concretes did decrease. The same trend followed for the flexural strength in which strength was reduced as the replacements level increased. The electrical resistivity increased with the increased of PET and RC replacement in concrete. Meanwhile, the water absorption of concretes increased with the increased of PET and RC replacement. Overall, the PET and rubber crumb can be utilized up to certain percentages in replacing fine aggregates in concrete

Properties of empty fruit bunches ash (EFBash) concrete / Mohd Amizan Mohamed @ Arifin and Assoc. Prof. Ir. Dr. Kartini Kamaruddin

Agricultural waste material that available to be used as a cement replacement in concrete mix is called Supplementary Cement Materials (SCM). One of the agricultural wastes that has potential to be used is the Empty Fruit Bunches (EFB). The EFBash offers advantages as SCM because it can prevent the environmental degradation and pollution. This ash will be tested with X- Ray Fluorescence Spectrophotometer (XRF) test to determine its chemical composition. The effects of using different percentages of EFBash replacement its compressive strength and durability will also be determined. For this research, the percentages of replacement of EFBash employed to cement (by weight) are 5%, 10%, 15%, 20% and 30%. The EFBash concrete of Grade 30 with 0.5, 0.55, 0.6 and 0.65 w/c ratios will be tested on its compressive strength and durability performance, i.e. by conducting compression test, permeability test and water absorption tests. The data will be taken from different ages i.e. 7, 14, 28, 60, 90 and 120 days. From this research, the optimum mix in achieving compressive strength and also the durability of EFBash concrete will be determined

Strength performance of sustainable mortar containing recycle sewage sludge ash (SSA) / Nurul Nazierah Mohd Yusri … [et al.]

Sewage sludge is a by-product generated within the wastewater treatment process. Severe concern arised as the sludge are massively been dumped to the landfill and it may affect the environment. Many studies had been conducted in reusing the sewage sludge as construction material, where it is one of the optional ways to solve the issue. In this study, dried sewage sludge was incinerated with two different temperatures in order to produce sewage sludge ash (SSA), which are 800°C and 1000°C. After few processes, this SSA then reused in mortar as cement replacement with the replacement percentage of 5%, 10%, 15% and 20% by weight. The strength performance of mortar specimens was investigated after 7, 28, 60 and 90 days of curing. From the results, it is clearly showed that the compressive strength of all mortar specimens increased when the period of curing was prolonged. Moreover, almost all compressive strength of SSA mortars was higher than the control mortar. Therefore, there is potential to reuse this waste material as part of construction materials and hence, its plays an important role for future researches in minimisation of waste

Strength Performance of Blended Ash Based Geopolymer Mortar

Geopolymer is a based on inorganic alumino-silicate binder system. Geopolymeric materials are formed using materials that containing silica and aluminium such as fly ash and rice husk ash, which activated by alkaline solution. This paper presents the study on the effect of replacement of SSA in RHA based geopolymer, types of curing and different molarity of NaOH used on the strength of Sewage Sludge Ash (SSA) and Rice Husk Ash (RHA) based geopolymer mortar incorporating with three (3) different mix proportions. Based geopolymer mortar was synthesized from treated sewage sludge and rice husk undergoing incineration process in producing ashes, activated with sodium silicate and sodium hydroxide solution by ratio of 2.5:1 and solution to ash ratio of 1:1. Molarity of 8M and 10M NaOH were used. The percentages of SSA replacement were 0%, 10% and 20% by weight. Compressive strength was conducted at age 7, 14 and 28 days to see the development of strength with two curing regimes, which are air curing and oven curing (60°C for 24 hours). From the research conducted, the ultimate compressive strength (6.28MPa) was obtained at zero replacement of SSA taken at 28 days of oven curing with 10M of NaOH. This shows that RHA, which is rich in silica content is enough to enhance the strength of geopolymer mortar especially with high molarity of NaOH

Strength Performance of Blended Ash Based Geopolymer Mortar

Geopolymer is a based on inorganic alumino-silicate binder system. Geopolymeric materials are formed using materials that containing silica and aluminium such as fly ash and rice husk ash, which activated by alkaline solution. This paper presents the study on the effect of replacement of SSA in RHA based geopolymer, types of curing and different molarity of NaOH used on the strength of Sewage Sludge Ash (SSA) and Rice Husk Ash (RHA) based geopolymer mortar incorporating with three (3) different mix proportions. Based geopolymer mortar was synthesized from treated sewage sludge and rice husk undergoing incineration process in producing ashes, activated with sodium silicate and sodium hydroxide solution by ratio of 2.5:1 and solution to ash ratio of 1:1. Molarity of 8M and 10M NaOH were used. The percentages of SSA replacement were 0%, 10% and 20% by weight. Compressive strength was conducted at age 7, 14 and 28 days to see the development of strength with two curing regimes, which are air curing and oven curing (60°C for 24 hours). From the research conducted, the ultimate compressive strength (6.28MPa) was obtained at zero replacement of SSA taken at 28 days of oven curing with 10M of NaOH. This shows that RHA, which is rich in silica content is enough to enhance the strength of geopolymer mortar especially with high molarity of NaOH

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

Abstract 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

A prospective multicenter randomized controlled trial to evaluate the efficacy of chitosan hydrogel paste in comparison to commercial hydroactive gel as a wound bed preparation

Background This clinical trial aimed to evaluate the clinical efficacy of chitosan derivative hydrogel paste (CDHP) as a wound bed preparation for wounds with cavities. Methods This study enrolled 287 patients, with 143 patients randomized into the CDHP group (treatment) and 144 patients randomized into the commercial hydro�active gel (CHG) group (control). The granulation tissue, necrotic tissue, patient comfort, clinical signs, symptoms, and patient convenience during the application and removal of the dressing were assessed. Results The study was completed by 111 and 105 patients from the treatment and control groups, respectively. Both groups showed an increasing mean percentage of wound granulation over time when the initial wound size and comorbidity were adjusted (F(10,198) =4.61; p < 0.001), but no significant difference was found between the groups (F(1,207)= 0.043; p ¼ 0.953). The adjusted mean percentage of necrotic tissue of both groups showed a significant decrease over time (F (10,235) = 5.65; p <0.001), but no significant differences were found between the groups (F (1,244)= 0.487; p ¼ 0.486). Conclusion CDHP is equivalent to CHG and is an alternative in wound management and wound bed preparation for wounds with cavitie