Utilisation of nano materials in enhancing strength and durability properties of ultra high performance concrete (UHPC) / Muhd Norhasri Muhd Sidek

Hydration gel (C-S-H) is major component in binding of concrete and refining of the C-S-H gel is difficult to be done by using micro based materials. For this research, inclusion of nano materials in UHPC is expected to overcome the problem by providing ultra filler effect. In this study, the utilisation of nano material in UHPC was done by using additive or replacement method for cement and UHPC mix and generated based on a series of trial modified mixes originally formulated by previous researchers. For this research, two types of nano materials were selected. Firstly, nano kaolin samples were prepared from kaolin using milling and then underwent calcination process to produce nano metakaolin. Secondly, nano clay was provided by Sigma (M) and underwent calcination process to convert to nano metaclay. Characterisation of cementitious materials were confirmed by its particle size, chemical composition and morphology properties and evaluated using Laser particle Analyser, X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). UHPC mixes were developed by incorporating nano materials with (addition) and without (replacement) addition of metakaolin. The inclusion of nano materials as an additive and cement replacement material (without metakaolin) based on percentage of increment from 1, 3, 5, 7 and 9 %. For additive approach, addition of metakaolin was fixed to 10%. The utilisation of nano materials was assessed in terms of its cementitious, microstructures and chemical phases, strength and durability properties. In cementitious properties, cement paste were determined in terms of setting time and compressive strength. In fresh state, workability of UHPC was determined by using slump test. For strength properties compressive and flexural strength were tested. Finally, durability properties were assessed based on porosity and water absorption characteristics. UHPC specimens, containing nano materials were assessed its chemical phases and microstructure using XRD and SEM examination. Moreover, data from strength and durability properties was optimise by using Design Expert Software and mathematical equation generated. It was found that, particles of nano materials performed different morphology as compared to the OPC, kaolin and metakaolin. For cement paste, inclusion of nano materials as addition or replacement increase the water demand but also increase compressive strength as compared to the OPC and metakaolin pastes. Strength and durability properties of nano materials enhances the UHPC performance by refining microstructure, promoting pozzolanic reaction and creating nucleation process and proves from the result provided by XRD pattern and SEM micrograph analysis

Kesan Keadaan Pengawetan Dan Pendedahan Terhadap Prestasi Kekuatan Dan Ciri-Ciri Ketahanlasakan Konkrit Mengandungi Metakaolin

Kesan keadaan pendedahan terhadap prestasi kekuatan dan ciri-ciri ketahanlasakan konkrit yang mengandungi metakaolin (MK) telah dikaji. MK telah dihasilkan melalui proses pengkalsinan ke atas kaolin yang didapati daripada sumber tempatan, pada suhu 700°C selama 3 jam. MK telah digunakan sebagai bahan gantian separa terhadap simen Portland biasa (OPC) berasaskan gantian jisim-ke-jisim pada tahap gantian 5, 10 dan 15 %. Nisbah campuran konkrit dikekalkan untuk semua campuran, dengan nisbah air/pengikat yang malar dan dos superpemplastikan yang sama, untuk mengasingkan kesan tahap gantian MK. The effect of exposure conditions on the strength performance and durability characteristics of concrete containing metakaolin (MK) has been investigated. The MK was produced by calcining kaolin obtained from a local source at a temperature of 700°C for 3 hours. The MK was used to partly replace the ordinary Portland cement (OPC) by direct replacement method on mass-for-mass basis at replacement levels of 5, 10 and 15 %. The mix proportions were kept nominally the same, with constant water/binder ratio and the same superplasticiser dosage for all concrete mixes, so as to isolate the effect of MK replacement levels

Influence of Calcination on Mineralogical and Strength Properties of Self Activated Green Material (SAGreM)

Concrete is an alkaline activated material consist of lime which contribute from limestone. This SAGreM has potential to be supplementary cementitious material because of the oxide content most similar with cement. SAGreM is a new sources generated from recycling of industrial waste which has similar affect to limestone. The purposed of this study is to investigate the mineralogical composition, particle size distribution and strength development of difference calcination temperature of SAGreM and the effect after activation with water. The mineralogical properties were investigated using by x-ray fluorescence and x-ray diffraction. The mineralogical test results showed that the SAGreM consists of calcite, free lime, and probably a crystal phase. SAGreM creates very well reactivity with water and gain the strength 4.85 MPa at 28 days in ambient condition exposure

Experimental Investigation of Ultrasonic Pulse Velocity (UPV) Test Specimen in assessing the Strength of Steel Fiber Reinforced Concrete Structure

This study aims to conduct the Ultrasonic Pulse Velocity (UPV) test and compressive strength test of Steel Fiber Reinforced Concrete (SFRC). This paper also examines the correlation of UPV test data and compressive strength test data for SFRC specimens. The experiments were carried out with the same value of the water-cement ratio, superplasticizer but different fiber volumes of steel fiber. Twelve prism sizes 100mm x 100mm x 500mm were casted and 0.5%, 1.0%, and 1.5% of steel fiber reinforced concrete were added and the prisms undergone curing for 7, 14 and 28 days. The highest value of the UPV test at the x-axis is SFRC-0.5%, 6.26 km/s at seven days and 6.8377 km/s at 14 days. The highest value of the UPV test at the y-axis is SFR-0.5%, 6.68 km/s at seven days and 6.34 km/s at 28 days. The grading is still in the excellent concrete quality based on BS1881. The highest value of compressive strength is SFRC-1.0%, 193.2 MPa at 14 days. The R-squared value for the correlation coefficient between UPV result and the compressive strength result at the x-axis and y-axis is 0.9963 and 0.9966 respectively which is near to 1.0 and can be considered as strongly correlated. The correlation equation obtained can be used to predict compressive strength based on UPV data for steel fiber addition up to 1.5% volume.  Thus, it can be concluded that percentage of steel fiber added, affect the strength of the tested concrete specimens and the optimized value of steel fiber added is at 1% in this stud

X-Ray Fluorescence, Strength Testing and 3D-Analysis of Steel Fibre Reinforced Concrete Specimen

This study was focused on steel fiber reinforced concrete (SFRC) specimens subjected to X-Ray Fluorescence (XRF), flexural strength testing, Compressive Strength Test and Rebound Hammer Test method. The experimental result of compression strength was analyzed by 3D Analysis using Stat-Ease Design-Expert V13 to correlate the compressive strengths and compare it to the elemental composition of the concrete structure. The result showed that the amount of Calcium Oxide (CaO) in the sample was lower than the composition of Ordinary Portland Cement (OPC) used. Decreasing of calcium oxide for increase proportion of steel fibre samples show the reaction of cement behaviour into concrete properties mixed with other material properties. Thirty-six (36) beam samples 100mm x 100mm x 500mm and twelve (12) cube samples of 100mm x 100mm x 100m were prepared with a different portions of steel fibre and RC structure as control samples. The percentages of steel fiber used were 0.5%, 1.0% and 1.5% to determine the optimum dosage. All samples were cured for 7, 14 and 28 days. It can be concluded that the analysis shows a low significant effect at an early aged concrete but showing a slightly increased in compression and flexural strength at later age

Strength and durability properties of nanometakolined ultra high performance concrete (UHPC) using response surface model (RSM) approach

Utilisation of Ultra High Performance Concrete (UHPC) is growing an interest in the world of construction today. Apart from that the inclusion of nano material in UHPC can enhance the performance and durability of UHPC. In this study, effect of nano metakaolin as additive in UHPC is reported. Inclusion of nano metakaolin from 1, 3, 5, 7 and 9% from weight of cement is compared to those plain UHPC and metakaolined UHPC. Effect of nano metakaolin in UHPC is done by four consecutive testing namely compressive strength, flexural strength, porosity and water absorption. All samples are prepared for testing’s from 3, 7, 28, 90, 180 and 365 days and subjected to water cure until age of testing. For analysis, Response Surface Model using historical data software is selected. A new equation is generated to relate on the effect of nano metakaolin in UHPC

Influence of metakaolin as partially cement replacement minerals on the properties of cement and concrete / Muhd Norhasri Mohd Sidek ...[et al.]

Metakaolin is a manufactured pozzolan produced by thermal processing of purified kaolinitic clay using electrical furnace. This study has examined the effect of Metakaolin on the properties of cement and concrete at a replacement level of 0%, 5%, 10% and 15%. The parameters studied were divided into two groups which are chemical compositions, water requirement, setting time and soundness test were carried out for cementitous properties. Workability, compressive strength and bending strength were test for concrete properties. Hardened concrete was cured under different type of curing conditions and tested.. The result showed that the inclusions of Metakaolin as cement replacement minerals have change some of the cementitous and concrete properties. This research reveals, the optimum effect for cementitous and concrete properties for metakaolin was 10%

Ultra high-performance concrete as alternative repair method: A review

This review paper discussed on the behavior of Ultra High-Performance Concrete (UHPC) in the concrete industry. Since the emergence of unique design of concrete, the needs of UHPC can contribute to alternative solutions to the High-Performance Concrete (HPC) and also normal concrete. In this review, definition, materials and techniques of producing, chemical analysis, and prediction software on previous and current works of UHPC were presented. Moreover, in this paper, the benefits of UHPC as compared to the types of concrete were also discussed. As a conclusion, UHPC needs to be implemented more in the construction nowadays. Extra strong, durable, and slimmer design of concrete structures can be an alternative to a sustainable and economic design that can last longer with less supervision

Simultaneous Monitoring on Corrosion-pH-Temperature using Multiplexed Fiber Bragg Grating Sensors Techniques in New RC Structure: A Review

Most recently, the use of Fiber Bragg Grating (FBG) sensors for monitoring and sensing the condition of structures in civil engineering applications has been developed significantly. FBG can be used for multi-point sensing through a single fiber optic and can be embedded inside the concrete. This paper is a review of current research and development of FBG sensor as a health monitoring system in concrete structure. FBG sensor offers the possibility of sensing due to different parameters like a strain, temperature, pH and displacement. In this paper, the advantages of FBG sensor in contrast to conventional electrical are reviewed. An introduction to fiber optic sensor technology and some of the applications which is still in its early infancy is presented. Two commonly used fiber optic sensors are briefly described namely corrosion sensor and pH sensor. Finally, shortcoming and deficiencies of existing corrosion monitoring technique are reviewed. Promising research efforts in multiplexed FBG sensor in-line one-fiber approach to realize simultaneous measurement of corrosion-pH-temperature monitoring for future research are discussed

Effect of Limestone Powder as an Additive and as Replacement of Self-Consolidating Lightweight Foamed Concrete

Concrete is the absolute most broadly utilized material in the development which must needs to guarantee attractive compressive quality and sturdiness. Mechanical properties of concrete are highly influenced by its density. A denser concrete generally provides higher strength. Numerous studies have been conducted for development of self-consolidating lightweight concrete (SCLWC) by investigating especially on their materials component and mix proportion. Commonly, considerations made by the researchers to produce SCLWC is by replacement of aggregates with alternative lightweight materials such as pumice, expanded clay, rubber granules and more or by adding foam agent. Besides, Limestone powder (LP) is one of concrete admixture that widely used as cement replacement. LP is proven can reduce energy consumption and resources from cement process, as well as effects the concrete properties. However, there are very few studies using only LP as main admixture for SCLWC. Therefore, the objectives of this study are to investigate the effect of limestone powder as an additive and as cement replacement in SCLW foamed concrete (SCLWFC) to the flowability and compressive strength. The experiment involves 3 types of SCLWFC which are normal mix; mixes without LP, additive mix; mixes with LP as an additive and replacement mix; mixes with and LP as cement replacement. Based on this study, the results indicated that the utilization of LP has positive effects to the flowability. Maximum value for slump flow was obtained when the LP as cement replacement at 40% and maximum value for compressive strength was obtained when the LP as an additive at 10%