Behaviour of steel fiber reinforced concrete slab due to volume fraction of fiber

Generally, fibers are commonly used in engineering material. The characteristics and properties of fiber influence the properties concrete. This has been proven by the previous research. In this research steel fiber is used to study the behavior of reinforced concrete slab due to volume fraction of fiber subjected to flexural test based on computer simulation. The application of steel fiber reinforced concrete in civil construction is the most popular due to its improvement in resistance to cracking, fatigue, abrasion, impact, durability, and conventional reinforced concrete. In this investigation,finite element simulation will be used to analyze the normal reinforced concrete slab and steel fiber reinforced concrete slab due to diffrent percentage of volume fraction with 1%, 1.5%, 2%, 2.5% and 3%. Through this simulation, the loading is applied and analyzed by the increments of every 2 KN up to ultimate failure. The results are obtained from the computer programming simulation and being compared with published experimental results. The result of the analysis indicates that, by using and adding steel fiber into the conventional reinforced concrete, it will influence the ductility, toughness, energy absorption and strength of the concrete

A review on performance of waste materials in self compacting concrete (scc)

Self-compacting concrete (SCC) was first developed in late 80’s in Japan. SCC is well known for its self-consolidation and able to occupy spaces in the formwork without any vibration and become new interesting topic in Construction and Building Materials Research. There were various SCC researches that have been carried out in Turkey, Malaysia, Thailand, Iran, United Kingdom, Algeria, and India.The aim of this review is to summaries the alternative material used in the mix design from 2009 to 2015 through available literature. It hascommon materials such as Limestone Powder (LP), Fly Ash (FA), Silica Fume and Granulated Blast Furnace Slag (GBFS). While there are many alternative or recycled material can be used in producing SCC. This review only focus on waste material fromMarble Powder (MP), Dolomite Powder (DP), Crump Rubber (CR), Recycled Aggregate (RA) and Rise Husk Ash (RHA).Each type of materialshassimilarity effect in fresh and hardened state of SCC. Therefore, this paper will provide significant and useful information to those new to SCC and fellow researchers for future studies on SCC

Fine recycled concrete aggregate as a material replacement in concrete production

As a fast and rapid growing nation, Malaysia undergoes a lot of development especially in construction field. Most of the building nowadays are being made mainly using concrete as it provides many favorable features such as satisfactory compressive strength, durability, availability, versatility and cost effectiveness. However, in pursuing the development era, sometimes the authorities overlooked about the construction and demolition (C&D) waste that had been created along the development progress. Construction and demolition waste is becoming a vital issue especially to the environmental aspect in many large cities in the world (Chen et al., 2002). Shen [1] describe C&D waste as the waste which generated from renovation, site clearing, demolition, construction, roadwork, land excavation and civil and building construction. Construction and Demolition (C&D) waste constitutes a major portion of total solid waste production in the world, and most of it is used in landfills .

Damage classification in reinforced concrete beam by acoustic emission signal analysis

Structural health monitoring (SHM) is known as assessment on damage detection in structural engineering. Nowadays, the application of SHM has been widely used especially on the continuous real time monitoring system with minimum labour involvement. One of the most excellent tools in SHM for real time monitoring system is Acoustic emission (AE). AE waves are high frequency stress wave generated by rapid release of energy from localised sources with a material, such as crack initiation and growth. High sensitivity to crack growth, the ability to locate source, passive nature and the possibility to perform real time monitoring are some of the attractive features of AE technique. In spite of these advantages, challenges still exist in using AE technique for monitoring applications especially in analysing recorded AE data as large volume of data are usually generated during monitoring. The need for effective data analysis in grading system can be linked into the three main objective of this research; (a) determine the grading system; (b) identify and discriminate the AE data parameter ; (c) and validate a new standard grading system for severity assessment. In this research, cyclic load test (CLT) method is the first method used for this evaluation system. This is a relatively new method that may provide a good insight into structural integrity status and also collaborates with the AE evaluation system. In the evaluation of AE data parameters, the conventional method known as parameter analysis (PA) was used to evaluate the reinforced concrete (RC) structure. This study has proposed and tested the absolute energy parameter in the evaluation for determining the damage level in RC structure. In addition, the cracks patterns in RC beam have been identified according to the type of cracking process and the cracks classifications by using the AE data parameters mainly AE amplitude, rise time, and average frequency. These data parameters have been analysed by using the statistical methods of b-value and RA value analysis. Quantification tool to assess the severity of the damage is extensively described in the practice applications. Even though different damage quantification methods have been proposed in AE technique, not all achieved universal approval or suitable for all situations. The IEA and ISA methods that involved the absolute energy and signal strength parameter were investigated for determining the damage level in RC structure. This was found to provide encouraging result for the analysis of AE data parameters in determining the damage grading system. By addressing this primary issue, it is believed that this thesis has helped to improve the effectiveness of AE technique for SHM in civil engineering

A review on performance of waste materials in self compacting concrete (scc)

Self-compacting concrete (SCC) was first developed in late 80’s in Japan. SCC is well known for its self-consolidation and able to occupy spaces in the formwork without any vibration and become new interesting topic in Construction and Building Materials Research. There were various SCC researches that have been carried out in Turkey, Malaysia, Thailand, Iran, United Kingdom, Algeria, and India.The aim of this review is to summaries the alternative material used in the mix design from 2009 to 2015 through available literature. It hascommon materials such as Limestone Powder (LP), Fly Ash (FA), Silica Fume and Granulated Blast Furnace Slag (GBFS). While there are many alternative or recycled material can be used in producing SCC. This review only focus on waste material fromMarble Powder (MP), Dolomite Powder (DP), Crump Rubber (CR), Recycled Aggregate (RA) and Rise Husk Ash (RHA).Each type of materialshassimilarity effect in fresh and hardened state of SCC. Therefore, this paper will provide significant and useful information to those new to SCC and fellow researchers for future studies on SCC

Relationship between ae signal strength and absolute energy in determining damage classification of concrete structures

The most efficient tools in real monitoring system is acoustic emission (AE). This technique can be used to identify the damage classifications in RC structure. This research paper will mainly focus on the utilization of signal strength and Absolute energy (AE signal) in determining on the damage quantification for RC beam subjected to cyclic load test. The beam specimens size (150 X 250 X 1900) mm were prepared in the laboratory and tested with the four point bending test using cyclic loading together with acoustic emission monitoring system. The results showed that the analysis of AE data parameters is capable of determining the damage classification in concrete structures and the data corresponded to the visual observations during the increased loading cycle

Investigation on the performance of crushed tires as cement replacement in concrete

The automobile has become an indispensable means of transportation for many households throughout the world. Thus, the disposal of vehicle tires represents a major environmental issue. Globally, more than 330 million tires are discarded every year and accumulated over the years in different countries [1]. In Malaysia, an estimated 150,000 tonnes of waste tires per year are dumped illegally. The disposal and reprocessing of tires are difficult since they contain complex mixtures of different materials such as rubber, carbon black, steel cord and other organic and inorganic minor components .

The suitability of coconut shell concrete as a replacements in term of mechanical and thermal properties – a review

The most critical issue in environment protection and natural resource conservation is waste management [1]. Changes in environment and an increase in population are the main causes of the many processes of deterioration which have altered the ecosystem of our planet, including the generation of municipal solid waste (MFS) [2]. Therefore, there is a need to reuse waste to create a greener and healthier place on earth. The usage of agricultural waste will be emphasized in this research. Being renewable, low-cost, lightweight, having high specific strength and stiffness have made agricultural waste ideal for use as construction materials [3]. Coconut shell, oil palm shell, oil palm clinker, corncob ash, and rice husk ash are all agricultural by-products. Although some of these materials can be used as animal feed or fuel in biomass power plants or boilers of various industrial sectors to produce steam, a lot of these materials are still disposed off into landfills or burnt. This leads to serious environmental problems..

Identifying the Crack Nature Using b-Value Acoustic Emission Signal Analysis

Concrete is an important constituent of structures. The strength performance of the concrete decrease due to several factors. Concrete suffers from deterioration at a later stage. Early and constant identification of concrete deterioration is necessary. Nowadays, non-destructive testing (NDT) is widely used especially on continuous real-time monitoring system with minimum labor involvement. It could also be used to discriminate the different types of damage occurring in reinforced concrete (RC) beam and real structure. In this research was monitored by using Acoustic Emission testing and it have several analysis such as RA-value, b-value, intensity signal analysis and historical index. To determine the acoustic emission signals for concrete structures and cracking identification this research using b-value analysis. b-value signals analysis contain useful information about damage mechanisms. A high b-value arises due to a large number of small AE hits, it representing new crack formation and slow crack growth, whereas a low b-value indicates faster or unstable crack growth accompanied by relatively high amplitude AE in large number. Reinforced concrete beams measuring of size 150 mm 250 mm 1500 mm were used during the acoustic emission test. A four-point load test was carried out on specimens until cracking occurred. The signals generated from the equipment were used for the analysis process, and the values are compared to define and summarise type of cracking and cracking processes

Thermal Conductivity of Crumb Rubber as Partial Sand Replacement and Recycled Aggregates as Partial Coarse Aggregate Replacement in Concrete

Disposal of waste tire rubber has become a major environmental issue worldwide and is increasing day by day, especially in Malaysia where carbon emission is among the highest in the world. Therefore, recycled waste materials are being used as construction materials in order to create new innovative products that are able to mitigate environmental pollution, reduce the cost of construction and improve the properties of concrete. This study discusses the utilisation of crumb rubber and recycled aggregates in concrete construction and the objective of this study is to determine the thermal conductivity of crumb rubber and compare the optimum strength of concrete materials. 12 cube samples measuring 200 200 100 mm containing different percentages of crumb rubber (0, 1, 2, 3, 4, and 5%) as fine aggregate substitute and 50% of recycled aggregates as coarse aggregate substitute were produced. The concrete grade used for these specimens is grade 35. The curing process was conducted on the samples to achieve the standard strength of concrete in 7 and 28 days. Therefore, the real strength of concrete was measured after the curing process. A slump test was conducted to determine the properties of crumb rubber. In addition, the samples were examined using the guarded hot box method to obtain the optimum percentage of crumb rubber as partial sand replacement in concrete for thermal conductivity. The results show that thermal conductivity (k-value) decreased slightly with the increase in crumb rubber content. However, the quality of concrete also slightly increased as the percentage of crumb rubber content increased. Lastly, based on the results, 5% of crumb rubber and 50% of recycled aggregates were suggested as the optimum percentages to be used in concrete as it achieved the lowest thermal conductivity compared to conventional concrete