Key Engineering Materials Vols. 594-595

Abstract: Every year earthquakes, tornadoes and other extreme windstorm cause fatalities or even kill people, devastate and millions of dollars worth of property. The likelihood that a tornado will strike building is a matter of probability. The study describes the analysis and design, the engineering process the new type of tornado safe room (Fig. 1) according to the FEMA guidance. It also evaluates the effects of in-fill frames and the linear response of reinforced concrete braced frames and comparison with frames with shear wall. The main conclusion drawn from this study is to elaborate that the masonry in-fills, are strongly influence the structural seismic response and contribute to the overall stiffness and can decrease drifts and displacements. Infill walls have significant role in the strength and ductility of RC framed structures and should be considered in both analysis and design globally. These walls make the structure significantly stiffer, and reduce the natural period of the structure. Locally, infill walls changed the load path, the distribution of forces between different elements of the structure, and the change the demand of forces on their adjacent elements of the bounding frame. Due to the high relative stiffness of the infill frames, they act as the main lateral load-resisting system and attract larger portions of the earthquake and tornado induced inertia forces.

Abstract: Development activities in construction sector have caused serious problems throughout the world as the natural resource depletion and produce large amounts of waste. In Malaysia, the main problem appeared when most of the waste was abandoned and not recycling. Such conditions can cause serious problem such as environmental pollution. This research utilizes aluminum waste as sand replacement in concrete. The use of these materials not only helps in the natural resources such as sand, aggregate, cement and other building. However, it also helps in reducing the manufacturing cost of the concrete. In addition, the reduction in the cost of waste disposal, saving manpower and protect the environment from the effects of pollution are the benefits derived from the use of waste materials. A study was conducted on the use of recyclable aluminum materials, as sand replacement material in concrete mix with replacement of 1%, 2% and 5%. Lab tests, including slump tests, compressive strength and water absorption were conducted in this study. As a result, samples containing 1% aluminum waste has better performance in terms of strength and containing 5% aluminum waste has good resistance to water absorption. Using aluminum waste in concrete is an interesting way in recycling waste thus can reduce waste disposal on sites and also can conserve the natural resources.

Abstract: Para Rubber Seed Shell (PRSS) as a coarse aggregate and coated by vulcanization and mixing epoxy natural rubber (ENR) was investigated. Natural rubber latex (60% DRC) was applied in two stages. Firstly stage, synthetic natural latex (ENR-35) solution was coated on the first layer of PRSS. After that, PRSS was coated by vulcanization in second layer. Then, pre-wetting was performed before mixing or casting the concrete for 5 days. Finally, CPRSS (Coated Para Rubber Seed Shell) was produced. The CPRSS aggregate was cast as self consolidation concrete (SCC) with different ratios of ordinary Portland cement: sand: CPRSS for 0.8-1: 0.6-0.85: 0.04-0.12 by weight, respectively and constant water/binder ratio at 0.45 throughtout this study. The ENR-35 was also used about 5% of the water content. However, the concrete was wrapped with polyvinyl sheet to prevent moisture loss during setting and curing in ambient temperature (29°C, 84%RH) for 28 days. The fresh concrete to slump test, harden concrete with bulk density and compressive strength of whole formulations was carried out to determine. The test result A8 indicted that the most ingredient suitable mixture of SCC involed cement: sand: CPRSS of 1:0.94:0.046. The SCC contained the slump as 120 mm, bulk density about 1916 kg/m³ and compressive strength was 37 MPa. Its was met specification of structural lightweight concrete. This beneficiation of SCC is also product as the green innovation building in terms of construction materials and resources, leaving minimal environmental impact, and having energy saving and eco-friendly materials.

Abstract: Over the centuries, concrete is commonly been used in construction world due to its properties. From the conventional concrete until the concrete that has been diversify with innovations, the usefulness is still the same, which is as building materials. One of the innovations called Self-Compaction Concrete (SCC). SCC is a type of concrete that does not require any mechanical compaction at all. This type of concrete will leveled and compacted under its self-weight. Such concrete will accelerate the placement, reduce the labor requirements needed for consolidation, finishing and eliminate environmental pollution. In terms of sustainability, previous researchers have recycled so many waste in SCC for example coal ash, silica fume, hydraulic lime, rice husk ash and fine limestone powder. Recently, recycling fly ash and bottom ash in SCC has grasped the attention of researchers as it demonstrated promising results. Furthermore, previous investigations already confirmed the potential of fly ash and bottom ash in replacing aggregates in SCC represents a better option than landfill and at the same time will decrease pollution problem especially in coal combustion area. This paper reviews the fly ash and bottom ash replacement in SCC.

Abstract: Low rise buildings and rural houses in Indonesia are often constructed with non-standard bricks. In some provinces, like West Java, fired clay and unfired soil lime bricks co-exist as non standard bricks. These bricks are traditionally produced in home run plants with little adherance to appropriate mix designs. These unfired soil lime bricks enter the market within 2 weeks of production, which inflicts potential loss to the buyers due to their low performance quality. The paper discusses strength improvements of these early age unfired bricks by adding natural fibers. Untreated coconut fibers with three different lengths (1 cm, 2.5 cm and 4 cm) were prepared for bricks reinforcements. The effects of 2%, 4% and 6% fiber addition to the strength of bricks were investigated. The bricks reinforced with 4% fiber content resulted in better strengths compared to those reinforced with other percentage of fibers. The effect of fiber length uniformity to the bricks strength was also evaluated. A 4% non-uniform fiber addition, which constitutes 1/3 part each of 1 cm, 2.5 cm and 4 cm average fiber length, was investigated. The results show that unfired bricks added with uniform fiber resulted in better performances compared to those added with non-uniform fibers. Higher compressive and bending strengths, compared to those strengths of unfired plain soil lime bricks and traditional soil lime bricks, could be achieved through fiber addition.

Abstract: Majority of people in Pengotan Village, Bangli Regency, Bali, Indonesia, do not have healthy and decent housing and neighborhoods. In 2008, the Central Statistics Board (BPS) announced that there were 134,804 poor households in Bali, including those in Bangli regency. Pengotan village is one of the nine villages in Bangli regency with the highest number of poor households (956,517). One of indicators that determine the poor household status is the poor quality of traditional houses inhabited, such as untilled floor (exposed soil) and low quality bamboo wall. Thus it is necessary to redevelop those houses into habitable houses that meet the standard of safety, health and comfort. This standard was set by the government through the Building Act No. 28/2002. Some aspects of the house redevelopment are the physical aspects of the house, redesign of the system of structure with the addition of brick walls and bamboo reinforced concrete frame, also replacement of roof and floor. This study aims to improve the physical safety and thermal comfort of the building.

Abstract: Lightweight foamed concrete is a concrete made by cement slurry mixed with foam so that foamed concrete that is much lighter than conventional concrete can be produced. The objectives of this study is to develop optimal pre-foamed lightweight foamed concrete and to achieve desired density of lightweight concrete that is below 2400 kg/m³. Three samples of concrete were batching with 0%, 25% and 50% of foam respectively under mixing ratio of 1:1:2 and foam dilution ratio 1:5 to obtain optimum result. Based on the result attained, the samples achieved the bulk density ranged from 1943 kg/m³ to 2305 kg/m³. In addition, other physical characteristics of this mixture of materials show that its water absorption for all the samples was increased from 6.508% to 11.889%. This trend of results was obtained if the volume of foam presented in the concrete were increased. Furthermore, the samples achieved compression strength ranged from 22.418 MPa to 32.229 MPa with presence of foam. In summary, with additional of fly ash and concrete sludge as aggregate it can help to produce comparable concrete composites with lighter density.

Abstract: The objective of this research is to investigate the potential use of Cameron Highland reservoir sediment in compressed brick production. The sediments can be classified as well-graded clayey sandy SILT and well-graded gravely SAND whereby the grain size is comparable to the grain size of sand and silt. The sediment was used as a 100 % replacement for the soils content in conventional soil cement bricks. Besides that, sodium bentonite, mica, fly ash and bottom ash are used as pozzolan to partially replace the cement in the sediment cement bricks. This paper presents the compressive strength of sediment cement brick incorporating sodium bentonite, mica, bottom ash and fly ash as partial replacement of cement. The total replacement of soils by Cameron Highland reservoir sediment (Mix 2) shows significant increase in compressive strength of the bricks compare to the conventional soil cement bricks (Mix 1), while partial replacement of 10 % pozzolan results in optimum strength. On the other hand, 10 % of bottom ash and 10 % of fly ash (Mix 13) as partial replacement of cement achieved the highest compressive strength. This implies that sodium bentonite, mica, fly ash and bottom ash can be used as pozzolan to partial replace the cement.

Abstract: Pressure-impulse (P-I) and charge weight-distance (CW-D) diagrams are widely used as quick damage assessment tools for reinforced concrete (RC) elements exposed to blast loading. Depending on the loading and element properties, the blast loading can induce different patterns of response and damage. Appropriate application of different simplified damage assessment tools for both far-field and near-field blast effects can be significantly challenging. This paper presents the comparison of the performances of two commonly used simplified damage assessment methods for RC elements exposed to explosive loading. Different aspects of the simplified damage assessment methods related to their construction and application for damage assessment are investigated. Some specific limitations of construction and use of P-I and CW-D diagrams are explored. Suitability of P-I diagrams for far-field and near-field blast effects is also explored. P-I diagrams are found to provide misleading damage assessment when applied for near-field blast effects.

Abstract: The use of waste and by-product materials as aggregate or cement replacement in concrete can provide a solution to reducing the negative impact of the concrete industry. This paper reports an investigation to produce green concrete by using oil palm shell (OPS) as coarse lightweight aggregate as well as ground granulated blast furnace slag (GGBFS) as supplementary cementing material subjected to different curing conditions. Test results show that it is possible to produce green structural lightweight aggregate concrete containing 50% waste materials (by volume of concrete) with 28-day compressive strength of about 33 MPa. Data show that OPS concrete is very sensitive to curing, especially when GGBFS is used as a supplementary cementitious material.