The effect of eccentricity at beam support to beam stiffness

A beam reacts to loading through bending action. Therefore, beam bending stiffuess can be represented by deflection. Theoretically, beam stiffuess is governed by span length, elastic modulus, moment of inertia and support type. In the analytical analysis, beams are assumed simply supported or fixed supported However, based on real cases and lab experiments there are other factors that are not included theoretical equation but effect to the beam stiffuess Factors such as eccentricity between beam neutral axis and beam support (vertical eccentricity), pour stop stiffuess in composite beam/slab effect and column size effect were analyzed in this study. The effects were studied using plane stress element finite. Pour stop stiffuess were modelled using spring element. From the analysis, vertical eccentricity does not give significant effect to beam stiffuess and it can be neglected. The pour stop provides stiffuess of 25000kN/m at the outer support. Beam deflection is independent with column deflection when column width is three times bigger than beam depth

Mechanical properties and thermal behaviour of two-stage concrete containing palm oil fuel ash

Two-stage concrete (TSC) is a special type of concrete which is made by placing coarse aggregate in a formwork and injecting a grout either by pump or under the gravity force to fill the voids. Over the decades, the application of supplementary cementing materials in conventional concrete has become widespread, and this trend is expected to continue in TSC as well. Palm oil fuel ash (POFA) is one of the ashes which has been recognized as a good pozzolanic material. This paper presents the experimental results on the performance behaviour of POFA in developing physical and mechanical properties of two-stage concrete. Four concrete mixes namely, TSC with 100% OPC as a control, and TSC with 10, 20 and 30% POFA were cast, and the temperature growth due to heat of hydration and heat transfer in the mixes was recorded. It has been found that POFA significantly reduced the temperature rise in two-stage aggregate concrete and delayed the transfer of heat to the mass of concrete. The compressive and tensile strengths, however, increased with the replacement of up to 20% POFA. The results obtained and the observation made in this study suggest that the substitution of OPC by POFA is beneficial, particularly for prepacked mass concrete where thermal cracking due to extreme heat rise is of great importance

The Effect of Dry Mix Sodium Hydroxide onto Workability and Compressive Strength of Geopolymer Paste

The production of ordinary Portland cement (OPC) consumes considerable amount of natural resources, energy and at the same time contribute in high emission of CO2 to the atmosphere. A new material replacing cement as binder called geopolymer is alkali-activated concrete which are made from fly ash, sodium silicate and sodium hydroxide (NaOH). It is proven that geopolymer has excellent reaction resistance to both conditions which is in acid and salt environment hence the strength escalated as the curing time and temperature increased. The NaOH are available in pellet form and needs to be dissolved in water before mixing with sodium silicate to form alkaline solution. The alkaline solution mixed with fly ash producing alternative binder to OPC binder in concrete named geopolymer paste. Geopolymer paste acts as binder in concrete and known as geopolymer concrete. The time needed for the NaOH was 24 hours until it fully dissolved in water and cooled to room temperature. This study aims to eliminate this process by using NaOH in solid form as part of dry mixtures together with fly ash before sodium silicate liquid and water poured into the mixture. The amount of NaOH solids were based on 10M concentration. The workability test is in accordance to ASTM C230. Fifty cubic mm of the geopolymer paste were prepared with fly ash to alkaline solution ratio of 1: 0.5 and the curing regime of 80℃ for 24 hours with 100% humidity were implemented. From laboratory test, the workability of dry method geopolymer paste decreased. The compressive strength of the dry mix of NaOH showed 55% strength reduction compared with conventional geopolymer paste casting method compared to the wet mix method while the workability has dropped 58.4% compared to wet mix

Field Performance of a Constructed Litter Trap with Oil and Grease Filter using Low-cost Materials

The current study was conducted to develop a litter trap by using crushed clay as an adsorbent media filter to reduce oil and grease (O&G) contents in residential wastewater and then to prevent the degradation of the environment and natural water bodies. Clay acts as a magnet, drawing the oil molecules out of the water and causing them to attach to the surfaces of the clay. The trap was built using Polyvinyl chloride (PVC) pipe and bamboo and installed at site-specific discharge points of storm water for removal of O&G. A total of twenty-four (24) wastewater samples were collected before and after the filtration The design achieved 94% of O&G removal. However, the removal efficiency deepened on the rainfall intensity, the increasing of rainfall effect negatively on the removal percentage of O&G. Nonetheless, the designed system exhibited a potential to remove O&G from the residential wastewater

Field performance of a constructed litter trap with oil and grease filter using low-cost materials

The current study was conducted to develop a litter trap by using crushed clay as an adsorbent media filter to reduce oil and grease (O&G) contents in residential wastewater and then to prevent the degradation of the environment and natural water bodies. Clay acts as a magnet, drawing the oil molecules out of the water and causing them to attach to the surfaces of the clay. The trap was built using Polyvinyl chloride (PVC) pipe and bamboo and installed at site-specific discharge points of storm water for removal of O&G. A total of twenty-four (24) wastewater samples were collected before and after the filtration The design achieved 94% of O&G removal. However, the removal efficiency deepened on the rainfall intensity, the increasing of rainfall effect negatively on the removal percentage of O&G. Nonetheless, the designed system exhibited a potential to remove O&G from the residential wastewater

Strength of Binary and Ternary Blended Cement Pastes Containing Palm Oil Fuel Ash and Metakaolin Exposed To Sodium Sulphate

The compressive strength of binary (BBCP) and ternary blended cement pastes (TBCP) containing Palm Oil Fuel Ash (POFA) and Metakaolin (MK) exposed to 3 % sodium sulphate solution has been studied. The ordinary Portland cement (OPC) was partially replaced with POFA and MK on mass-for-mass basis. All specimens were first cured for 28 days in normal water and subsequently subjected to full immersion in sodium sulphate solution for 150 days for the compressive strength evaluation. The results show that partial replacement of cement with POFA and MK improved the durability of the cement pastes by reducing the damage caused by sulphate attack

MECHANICAL PROPERTIES AND THERMAL BEHAVIOUR OF TWO-STAGE CONCRETE CONTAINING PALM OIL FUEL ASH

ABSTRACT: Two-stage concrete (TSC) is a special type of concrete which is made by placing coarse aggregate in a formwork and injecting a grout either by pump or under the gravity force to fill the voids. Over the decades, the application of supplementary cementing materials in conventional concrete has become widespread, and this trend is expected to continue in TSC as well. Palm oil fuel ash (POFA) is one of the ashes which has been recognized as a good pozzolanic material. This paper presents the experimental results on the performance behaviour of POFA in developing physical and mechanical properties of two-stage concrete. Four concrete mixes namely, TSC with 100% OPC as a control, and TSC with 10, 20 and 30% POFA were cast, and the temperature growth due to heat of hydration and heat transfer in the mixes was recorded. It has been found that POFA significantly reduced the temperature rise in two-stage aggregate concrete and delayed the transfer of heat to the mass of concrete. The compressive and tensile strengths, however, increased with the replacement of up to 20% POFA. The results obtained and the observation made in this study suggest that the substitution of OPC by POFA is beneficial, particularly for prepacked mass concrete where thermal cracking due to extreme heat rise is of great importance

The effect of eccentricity at beam support to beam stiffness

A beam reacts to loading through bending action. Therefore, beam bending stiffness can be represented by deflection. Theoretically, beam stiffness is governed by span length, elastic modulus, moment of inertia and support type. In the analytical analysis, beams are assumed simply supported or fixed supported. However, based on real cases and lab experiments there are other factors that are not included theoretical equation but effect to the beam stiffness. Factors such as eccentricity between beam neutral axis and beam support (vertical eccentricity), pour stop stiffness in composite beam/slab effect and column size effect were analyzed in this study. The effects were studied using plane stress element finite. Pour stop stiffness were modelled using spring element. From the analysis, vertical eccentricity does not give significant effect to beam stiffness and it can be neglected. The pour stop provides stiffness of 25000kN/m at the outer support. Beam deflection is independent with column deflection when column width is three times bigger than beam depth

Performance of geopolymer concrete in fire

High strength geopolymer concrete was developed and its performance in fire was assessed in this study. Geopolymer concrete is a cementless concrete which utilises waste from coal power plant, fly ash. Manufacture of geopolymer concrete is responsible for lower carbon dioxide emission than conventional concrete due to the replacement of cement with fly ash for concrete binder. Large scale high strength geopolymer concrete wall panels were tested under the most severe fire simulating a hydrocarbon fire. Findings from this study make a substantive contribution in producing an environmental friendly concrete with good fire resistance

The Spalling of Geopolymer High Strength Concrete Wall Panels and Cylinders Under Hydrocarbon Fire

Concrete structures were designed to withstand various types of environment conditions from mild to very severe conditions. Fire represents one of the most severe environmental conditions to which concrete structures may be subjected especially in close conduct structure like tunnel. This paper focuses on the spalling of geopolymer high strength concrete exposed to hydrocarbon fire for minimum 2 hours. From the fire test, geopolymer concrete can be classified as a good fire resistance construction materials based on spalling performance of high strength concrete when exposed to hydrocarbon fire. A maximum of 1% (excluding water moisture loss) of spalling recorded for high strength geopolymer concrete wall panel. No explosive spallings were observed for high strength geopolymer concrete