Prediction of Loss on Ignition of Ternary Cement Containing Coal Bottom Ash and Limestone Using Central Composite Design

The effect of CBA/CBA-L ratio and the cement replacement on the Loss on ignition (LOI) of ternary cement blends was investigated using central composite design approach in the prediction of LOI of ternary cement blend comprising of Ordinary Portland cement, coal bottom ash and Limestone. LOI is an essential technique employed in the determination of the quality of the cement blend which can be achieved by heating a sample strongly at a specified temperature to enable release of volatile components until the weight remains constant. In this study, monitoring of the LOI of the various cement blends conducted dependent on cement replacement and coal bottom ash to coal bottom ash-limestone ratio (CBA/CBA-L ratio) via thermogravimetric analysis (TGA) and X-ray fluorescence (XRF) analysis. The CBA/CBA-L ratio was varied from 0.25-0.75 while the cement replacement ranges from 20-40%. The significance of these factors within the specified ranges considered was evaluated using analysis of variance.The aim of the study was to evaluate the effect of CBA/CBA-L ratio and cement replacement in the prediction of LOI for ternary cement blends by employing Face Central Composite Design. Analysis of variance results indicated that the LOI prediction via XRF analysis was better than that of TG analyses in which both satisfied Two-Level Factorial model. It was observed from the predictive models that the LOI of the ternary cement decreased as the CBA/CBA-L ratio was increased while LOI of the ternary cement blend increased as the cement replacement was increased. An increase in both CBA/CBA-L ratio and cement replacement resulted in a decrease in the LOI of ternary cement. The cement replacement level of the ternary cement blends indicated a stronger influence on LOI compared to the CBA/CBA-L ratio which was indicated by a significantly high F value for cement replacement compared to CBA/CBA-L ratio.The LOI results from XRF analysis were also found to significantly predict the LOI of the ternary cement blend compared to TGA with Regression value of 99.96% against 97.36% respectively. The CBA/CBA-L ratio and cement replacement were found to have a significant and interactive effect on the LOI of ternary cement blend for both XRF and TGA analyses

Potential of Orange Peel Ash as a Cement Replacement Material

The potential of Orange peel ash (OPA) as a cement replacement material was investigated with focus on the effect of OPA content on the physicomechnical properties such as consistency, setting times, soundness, compressive and flexural strengths of OPA-cement blend for cement replacement between 2.5-10% at 2.5% interval. The optimal calcination temperature and time of orange peel (OP) was achieved by calcining the OP at various temperature between (600 °C, 700 °C, 800 °C) and time (1 hr. and 2 hrs.) respectively. The chemical compositions of the various orange peel ashes were determined using X-ray fluorescence equipment and the optimal conditions was obtained at 600 °C and 2 hours. The consistency and setting time tests were conducted with a Vicat apparatus on the binary cement pastes in accordance to ASTM standards. Results indicated an increase in the water required for consistency as the OPA content was increased from 2.5-10 % which was attributed to the unburnt carbon content present in the ash. Similarly, a gradual increase in the cement replacement with OPA resulted in a prolonged setting time which was could be attributed to the diminution of the clinker content and the higher water requirement for normal consistence. The soundness of the OPA cement blend experienced an increase in free lime content as the OPA content rose from 2.5-10 %. Both compressive and flexural strengths were found to decrease as the OPA content was gradually increased whereas an increase in the strengths were observed as the curing days progressed. It was also observed that 5% cement replacement with OPA did not adversely affect the strength in comparison to the OPC control due to the pozzolanic reaction which resulted in the enhanced strengths especially at 28 days

The Behaviour of Finely Ground Bottom Ash in Portland Cement

The aim of this project was to assess the effects of finely ground MSWI bottom ash in Portland cement. Mortar mixes were prepared with 10% and 40% replacement of cement by ground IBA and then tested with regards to their material composition and engineering behaviour. IBA was found not to be inert, but showed some degree of reactivity. Replacement of cement with IBA was found to have no detrimental effects at low concentrations. This was not the case for 40% replacement, where cement replacement greatly affected strength, creep and drying shrinkage

Influence of Curing Age and Mix Composition on Compressive Strength of Volcanic Ash Blended Cement Laterized Concrete

This study investigates the influence of curing age and mix proportions on the compressive strength of volcanic ash (VA) blended cement laterized concrete. A total of 288 cubes of 100mm dimensions were cast and cured in water for 3, 7, 28, 56, 90 and 120 days of hydration with cement replacement by VA and sand replacement by laterite both ranging from 0 to 30% respectively while a control mix of 28-day target strength of 25N/mm2 (using British Method) was adopted. The results show that the compressive strength of the VA-blended cement laterized concrete increased with the increase in curing age but decreased as the VA and laterite (LAT) contents increased. The optimum replacement level was 20%LAT/20%VA. At this level the compressive strength increased with curing age at a decreasing rate beyond 28 days. The target compressive strength of 25N/mm2 was achieved for this mixture at 90 days of curing. VA content and curing age was noted to have significant effect (α 0.5) on the compressive strength of the VA-blended cement laterized concrete

Influences of chloride immersion on zeta potential and chloride in concentration of cement-based materials

In this paper, the zeta potential of freshly mixed cement paste and hardened cement pastes, as well as the concentration index, was measured. The influences of chloride concentration in mixing water and slag content on zeta potential of freshly mixed pastes were studied. A proposed model was expressed to explain the relationship of zeta potential and concentration index of hardened cement pastes immersed in chloride solution. The results showed that the increase of chloride concentration in mixing water and slag replacement improved the zeta potential of freshly mixed cement, the hydration rate and concentration of ions in mixed water affects the zeta potential. With the increase of chloride concentration in soaking solution, the chloride concentration index and zeta potential of hardened cement paste all gradually decreased. The addition of slag gave some changes on chloride in concentration and zeta potential. The relationship among chloride concentration index, chloride concentration in soaking solution and slag replacement revealed by Gouy-Chapman model was in good agreement with the measured results

Compressive Strength of Volcanic Ash/Ordinary Portland Cement Laterized Concrete

This study investigates the effect of partial replacement of cement with volcanic ash (VA) on the compressive strength of laterized concrete. A total of 192 cubes of 150mm dimensions were cast and cured in water for 7, 14, 21, and 28 days of hydration with cement replacement by VA and sand replacement by laterite both ranging from 0 to 30% respectively, while a control mix of 28-day target strength of 25 N/mm2 was adopted. The results show that the density and compressive strength of concrete decreased with increase in volcanic ash content. The 28-day, density dropped from 2390 kg/m3 to 2285 kg/m3 (i.e. 4.4% loss) and the compressive strength from 25.08 N/mm2 to 17.98 N/mm2 (i.e. 28% loss) for 0-30% variation of VA content with no laterite introduced. The compressive strength also decreased with increase in laterite content; the strength of the laterized concrete however increases as the curing age progresses

Performance of composite sand cement brick containing recycled concrete aggregate and waste polyethylene terepthalate

The reuse and recycling of waste materials from construction and demolition waste is one of the new concepts for brick manufacturing production. Construction and demolition debris refers to waste materials that result from the construction, renovation and demolition of buildings. Bricks are an important material for developing areas where manufacturers find it difficult to locate adequate sources due to the shortage of natural aggregate supply. Construction waste can be recycled to replace naturals resource or other competitive materials. This study aims to establish the sustainable properties for composite bricks using Recycle Concrete Aggregate (RCA) and Polyethylene Terephthalate (PET) waste bottles as sand aggregate replacement. RCA was obtained from crushed laboratory concrete cubes while PET bottles were collected around UTHM and Parit Raja areas. The objectives of this study are to determine the optimum cement-sand ratio (1:5, 1:6 and 1:7) for composite brick through density, compressive strength and water absorption tests, to investigate the mechanical properties and durability of composite sand cement bricks through shrinkage and carbonation tests, and to identify the optimum percentages of RCA and PET as sand aggregate replacement in composite bricks. For this study, the brick specimens were prepared using 25%, 50% and 75% of RCA and 1.0%, 1.5%, 2.0% and 2.5% of PET by volume of natural sand with a water-cement ratio of 0.6. The size of the RCA used measured less than 5 mm. Moreover, the size of the sieved waste PET granules was between 0.1 to 5 mm which made it physically similar to the size of fine aggregates. The bricks were cast in moulds measuring 215 mm in length, 103 mm in width, and 65 mm in depth. Three types of sand-cement ratios were used, namely 1:5, 1:6 and 1:7. The first stage of the study was the determination of the best sand-cement ratio through density, water absorption and compressive strength tests. The next stage was the determination of the optimum percentages of RCA and PET according to the shrinkage and carbonation tests. The overall results revealed that the best cement-sand ratio was 1:6. The density test indicates that the average density of composite bricks is lower compared to that of control bricks. The cement-sand ratio of 1:6 was the optimum value for all sample bricks. In addition, the percentage of water absorption for composite bricks was found to be satisfactory. It can be concluded that the optimal replacement of RCA and PET was R25P1 with a cement-sand ratio of 1:6 as it achieved the lowest values during the drying shrinkage and carbonation tests

Utilization of sawdust ash as cement replacement for the concrete production: a review

Cement is the main materials for the construction and it is very expensive. Considering the growing demand of cement, the researchers are probing towards the new cement replacement materials. To achieve the sustainable development, it is imperative to use supplementary cementing materials in the field of concrete engineering. Currently, numerous research has been conducted on the utilization of sawdust ash as a cement replacement in the production of green building material and an alternative means of wood waste minimization. The result of this research work has indicated that sawdust ash has a good potential to be utilized as replacement of ordinary Portland cement for the production of concrete. The aim of this review work is to summarize previous research studies on utilization of sawdust ash as a cement replacement. Hence, this review paper will provide the significant idea and valuable information for the fellow researchers working for the composite cement materials, supplementary cementing materials in the field of concrete technology and it is the considerable verdict that more research is deserved to be carried out on the development of high-strength concrete incorporating sawdust ash as a cement replacement