Maslina Jamil

On the Utilization of Pozzolanic Wastes as an Alternative Resource of Cement

Recently, as a supplement of cement, the utilization of pozzolanic materials in cement and concrete manufacturing has increased significantly. This study investigates the scope to use pozzolanic wastes (slag, palm oil fuel ash and rice husk ash) as an alkali activated binder (AAB) that can be used as an alternative to cement. To activate these materials, sodium hydroxide solution was used at 1.0, 2.5 and 5.0 molar concentration added into the mortar, separately. The required solution was used to maintain the flow of mortar at 110% ± 5%. The consistency and setting time of the AAB-paste were determined. Mortar was tested for its flow, compressive strength, porosity, water absorption and thermal resistance (heating at 700 °C) and investigated by scanning electron microscopy. The experimental results reveal that AAB-mortar exhibits less flow than that of ordinary Portland cement (OPC). Surprisingly, AAB-mortars (with 2.5 molar solution) achieved a compressive strength of 34.3 MPa at 28 days, while OPC shows that of 43.9 MPa under the same conditions. Although water absorption and porosity of the AAB-mortar are slightly high, it shows excellent thermal resistance compared to OPC. Therefore, based on the test results, it can be concluded that in the presence of a chemical activator, the aforementioned pozzolans can be used as an alternative material for cement.

Development of a Zero-Cement Binder Using Slag, Fly Ash, and Rice Husk Ash with Chemical Activator

The increasing demand and consumption of cement have necessitated the use of slag, fly ash, rice husk ash (RHA), and so forth as a supplement of cement in concrete construction. The aim of the study is to develop a zero-cement binder (Z-Cem) using slag, fly ash, and RHA combined with chemical activator. NaOH, Ca(OH)2, and KOH were used in varying weights and molar concentrations. Z-Cem was tested for its consistency, setting time, flow, compressive strength, XRD, SEM, and FTIR. The consistency and setting time of the Z-Cem paste increase with increasing RHA content. The Z-Cem mortar requires more superplasticizer to maintain a constant flow of % compared with OPC. The compressive strength of the Z-Cem mortar is significantly influenced by the amounts, types, and molar concentration of the activators. The Z-Cem mortar achieves a compressive strength of 42–44 MPa at 28 days with 5% NaOH or at 2.5 molar concentrations. The FTIR results reveal that molecules in the Z-Cem mortar have a silica-hydrate (Si-H) bond with sodium or other inorganic metals (i.e., sodium/calcium-silica-hydrate-alumina gel). Therefore, Z-Cem could be developed using the aforementioned materials with the chemical activator.

Prediction of strength and slump of rice husk ash incorporated high-performance concrete

Abstract This paper describes the development of statistical models to predict strength and slump of rice husk ash (RHA) incorporated high-performance concrete (HPC). Sixty samples of RHA incorporated HPC mixes having compressive strength range of 42–92 MPa and slump range of 170–245 mm were prepared and tested in the laboratory. These experimental data of sixty RHA incorporated HPC mixes were used to develop two models. Six variables namely water-to-binder ratio, cement content, RHA content, fine aggregate content, coarse aggregate content and superplasticizer content were selected to develop the models and ultimately to predict strength and slump of RHA incorporated HPC. The models were developed by regression analysis. Additional five HPC mixes were prepared with the same ingredients and tested under the same testing conditions to verify the ability of the proposed models to predict the responses. The results of the prediction of the models showed good agreement with the experimental data. Thus the dev...

Modern architecture in the 21 st century

This paper presents the modern architecture in the current century. Modern architecture is a new architectural style that emerged in many countries in the decade after World War I. It was based on the “rational” use of modern materials, the principles of functionalist planning, and the rejection of historical precedent and ornament. Modern architecture was adopted by many influential architects and an architectural educator, gained popularity after the Second World War, and continues as a dominant architectural style for institutional and corporate buildings in the 21st century. According to this research, The Modern movement also referred to controversially as a style by some bound morality, technology and art together. Morality in that there was an aim to improve humanitys lot, notably whole scale demolition of slums to make way for clean modern housing. This paper presents the role of modernism in architecture. In this paper has been shown the influence of modernism in humanity and countries.

Modern Rammed Earth in Earth Architecture

Rammed earth is a technique for building walls using the raw materials of earth, chalk, lime and gravel. Rammed earth is a structural wall system built of natural mineral soils compacted in thin layers within sturdy formwork. People have been using various forms of earth to build structures for centuries. The ancient „rammed earth‟ building technique has been used in Neolithic architecture sites and modern buildings alike. From underground green homes to other futuristic green houses. Modern architecture is a new architectural style that emerged in many countries in the decade after World War I. It was based on the “rational” use of modern materials, the principles of functionalist planning, and the rejection of historical precedent and ornament. This paper is included many examples of structures made from rammed earth using modern architecture. The result has shown the earthen buildings create safer, more people-friendly buildings. The earthen buildings are very low in embodied energy, and extremely comfortable to live in based on modern architecture.

The Important Role of Chogha Zanbil in Earth Architecture Based on Material, Structural and Architectural Aspects

Earthen buildings come in a vast variety of shapes and sizes, made from materials like fired clay, compressed dirt and a mixture of clay, sand, straw and water. People have been using various forms of earth to build structures for centuries. The aim of this paper is to find better knowledge about Chogha Zanbil as an earth architecture based on material, structural and architectural conditions. Earth architecture includes vernacular and historical architecture drawn from many cultures and periods in different countries. Chogha Zanbil’s materials are included mud bricks and walls that are earth building’s elements. The result has shown mud bricks as good materials can be develop in new buildings and applications.

Underground soil and thermal conductivity materials based heat reduction for energy-efficient building in tropical environment

In this paper, an alternative way of releasing heat of building is investigated in order to reduce energy demand of building built in tropical environment. Underground soil is considered as a source for extracting heat from building through thermal conductivity pipes. Thermal conductivity pipes are considered to be fixed on the inner faces of the walls and their lower part to be inserted to the ground where temperature is lower than the indoor temperature. The entire analyses were done numerically using ANSYS 11. Heat flow between two systems was studied and the performance of the thermal conductivity pipes was examined. The room temperature in the presence of thermal conductivity pipes as well as mechanical cooling system and other passive energy-efficient techniques of building were also studied. The underground soil was demonstrated to act as a heat sink and absorb heat released from the rooms and the thermal conductivity pipes would play a role in transferring heat from the rooms to the underground soil. The system works efficiently when it is used with other mechanical or passive cooling systems. In this way, energy saving measure could be possible to reduce building temperatures by around 3℃.

Transmission Loss Computed of Star Topology Sensor Network Base on DT, RED and SFQ Buffer Mechanism for Overseeing High Rise Building Structural Health

Wireless sensor network is the new invention applying for detects the damage of the civil infra-structural health. Recently, Wireless sensor network are widely used because it’s low cost, portable, easy to run, install, reconfigured, easy maintenance. The coverage area becoming a crucial issue for multi-hop sensor network locally or remotely historical or high-rise structural health overseeing. The objective of this article is to design star topology sensor network and loss investigation of the sensor node transmit signal at the base station. The loss of the received signal are computed at base station based on DT (Drop Tail), RED (Random Early Discard), SFQ (Stochastic Fair Queuing) buffer mechanism.

Influence of Morphology of Cathode-Ray Tube Glass as Coarse Aggregates on Compressive Strength and Water Absorption of Concrete

The study on the substitution for natural coarse aggregates using waste CRT funnel glass in spherically shapes is still limited. In this paper, the waste CRT glass has been processed to form a spherical CRT glass (GS) and crushed CRT glass (GC), which were used as a coarse aggregate in concrete production. Results indicated that the inclusion of GS and GC has lower the compressive strength and decreased the rate of capillary water absorption of concrete. It was demonstrated that the morphology properties of GS and GC (shape, surface texture, size, grading) is significantly affected the concrete properties.

Effect of Heavy Metal on Complex Permittivity Characteristics of Saturated Sand

In this paper, experiments have been carried out to investigate the effect of heavy metals on the complex permittivity characteristics of saturated soil in the frequency range of 1–1,000 kHz. The effect of Pb and Fe concentration on the complex permittivity was explored. Electrode polarization was observed at low frequencies (200–300 kHz). Therefore, at frequencies less than 200 kHz, presence of Pb and Fe in saturated soils increases the real part of the complex permittivity, while a decrease in the real part of the complex permittivity was observed at frequencies higher than 300 kHz. The imaginary part of the complex permittivity increases with increasing heavy metal concentrations over all frequency ranges. This can be attributed to the increase of current conduction. The results indicate that the measured complex permittivity of saturated soil can be used as a means of detecting heavy metal contaminations in soil.