scholarly journals Assessment and optimization of thermal and fluidity properties of high strength concrete via genetic algorithm

2016 ◽  
Vol 7 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Barış Şimşek ◽  
Emir Hüseyin Şimşek
Keyword(s):  
Heat Transfer ◽  
Genetic Algorithm ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
High Strength Concrete ◽  
High Strength ◽  
Strength Concrete ◽  
Overall Heat Transfer Coefficient ◽  
Binder Ratio ◽  
Water To Binder Ratio

This paper proposes a Response Surface Methodology (RSM) based Genetic Algorithm (GA) using MATLAB® to assess and optimize the thermal and fluidity of high strength concrete (HSC). The overall heat transfer coefficient, slump-spread flow and T50 time was defined as thermal and fluidity properties of high strength concrete. In addition to above mentioned properties, a 28-day compressive strength of HSC was also determined. Water to binder ratio, fine aggregate to total aggregate ratio and the percentage of super-plasticizer content was determined as effective factors on thermal and fluidity properties of HSC. GA based multi-objective optimization method was carried out by obtaining quadratic models using RSM. Having excessive or low ratio of water to binder provides lower overall heat transfer coefficient. Moreover, T50 time of high strength concrete decreased with the increasing of water to binder ratio and the percentage of superplasticizer content. Results show that RSM based GA is effective in determining optimal mixture ratios of HSC.

Effects of Two Polypropylene Fibers on the Properties of High Strength Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 1328-1331
Author(s):  
Bai Rui Zhou ◽  
Dong Dong Han ◽  
Jian Hua Yang ◽  
Yi Liang Peng ◽  
Guo Xin Li
Keyword(s):  
Portland Cement ◽  
Modulus Of Elasticity ◽  
High Strength Concrete ◽  
Polypropylene Fiber ◽  
High Strength ◽  
Polypropylene Fibers ◽  
Strength Concrete ◽  
Reticular Fiber ◽  
Binder Ratio ◽  
Water To Binder Ratio

Portland cement, crushed stone, sand and superplasticizer were used to obtain a high strength concrete with a low water to binder ratio. A reticular polypropylene fiber and a single polypropylene fiber were used to improve the strength of the high strength concrete, but the effects of the two fibers on the slump and strengths were quite different. The reasons of the differences were the surface area and the modulus of elasticity of the fibers. The results show the reticular fiber was better to used in high strength concretes.

Flexural and Splitting Tensile Strength of High Strength Concrete with Diatomite Micro Particles as Mineral Additive

2020 ◽  
Vol 402 ◽  
pp. 50-55 ◽  
Author(s):  
Muttaqin Hasan ◽  
Aulia Desri Datok Riski ◽  
Taufiq Saidi ◽  
Husaini ◽  
Putroe Nadhilah Rahman
Keyword(s):  
Tensile Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Tensile Tests ◽  
Splitting Tensile Strength ◽  
Strength Concrete ◽  
Micro Particles ◽  
Mineral Additive ◽  
Binder Ratio ◽  
Water To Binder Ratio

This paper presents the flexural and splitting tensile strength of high strength concrete (HSC) with diatomite micro particles (DMP) as a mineral additive. In order to have micro particles, the diatomite from Aceh Besar District was ground and sieved with sieve size of 250 mm. The particles were then calcined at the temperature of 600 °C for 5 hours. Four mixtures were designed with different DMP to binder ratio (DMP/b). The ratio was 0%, 5%, 10% and 15%, and the water to binder ratio was 0.3. Four beam specimens with a size of 10 cm × 10 cm × 40 cm and four cylinder-specimens with 10 cm diameter and 20 cm high were prepared for each mixture. Flexural and splitting tensile tests were conducted based on ASTM C78 and ASTM C496/496M. The maximum flexural strength was reached at DMP/b of 5% while the maximum splitting tensile strength was reached at DMP/b of 0%.

Heat exchanger network retrofit throughout overall heat transfer coefficient by using genetic algorithm

2016 ◽  
Vol 94 ◽  
pp. 274-281 ◽  
Author(s):  
Totok Ruki Biyanto ◽  
Enrico Kevin Gonawan ◽  
Gunawan Nugroho ◽  
Ridho Hantoro ◽  
Hendra Cordova ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Genetic Algorithm ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Heat Exchanger Network ◽  
Overall Heat Transfer Coefficient

scholarly journals Influence of internal curing on the properties of non-fibrous high strength concrete—A critical review

2021 ◽  
Vol 1 (3) ◽  
pp. 1-6
Author(s):  
Ferhad Rahim Karim
Keyword(s):  
High Strength Concrete ◽  
Autogenous Shrinkage ◽  
High Strength ◽  
Internal Curing ◽  
Degree Of Hydration ◽  
Strength Concrete ◽  
Hydrated Cement Paste ◽  
Future Performance ◽  
Binder Ratio ◽  
Water To Binder Ratio

The demand for the construction of high-strength concrete in the civil engineering zone is growing, particularly in the last couple of years, due to the construction of sustainable and economic buildings with an extraordinary slim design. Concrete curing in construction is an operative manner and essential to provide that concrete structures meet future performance and durability. High-strength concrete has a low water-to-binder ratio; proper concrete curing is important to ensure its planned performance and durability. Conventionally, exterior curing applied after placing and casting concrete stays warm and moist to provide continued cement hydration. Lately, theoretically and experimentally comprehends that internal curing is an important tool to provide additional moisture in the concrete to enhance cement's hydration. Internal curing of high-strength concrete is an active technique to lessen or even remove autogenous shrinkage and effects on chemical shrinkage, dry shrinkage, etc. Most studies recently have emphasized that a reduction in high strength concrete mixtures' shrinkage is due to internal curing, and the compressive strength can increase higher in mixtures with LWA or SAP than in mixtures without this agent rising degree of hydration by providing extra water in the hydrated cement paste. However, the use of internal curing leads to improving the durability of high-strength concrete.

Effects of Three Steel Fibers on the Properties of High Strength Concrete

2013 ◽  
Vol 753-755 ◽  
pp. 576-580 ◽  
Author(s):  
Hui Lian ◽  
Yun Fei Zhang ◽  
Jiang Tao Xin ◽  
Jian Hua Yang ◽  
Guo Xin Li
Keyword(s):  
High Strength Concrete ◽  
Bending Strength ◽  
Steel Fiber ◽  
Steel Wire ◽  
High Strength ◽  
Diameter Ratio ◽  
Steel Fibers ◽  
Strength Concrete ◽  
Binder Ratio ◽  
Water To Binder Ratio

Portland cement, crushed stone, sand and superplasticizer were used to obtain a high strength concrete with a low water to binder ratio. Three steel fibers such as waste steel wire, corrugated steel fiber and arch steel fiber were added into the high strength concrete. The effects of the three fibers on the slump and the strengths such as compressive strength, tensile strength and bending strength were researched. The reduction of the slump and the increasing of the strength of the concrete with the arch steel fiber were the most significant due to the highest length-diameter ratio.

Influence of Metakaolin on Strength and Microstructure of High-Strength Concrete

2012 ◽  
Vol 509 ◽  
pp. 33-39
Author(s):  
Zhong He Shui ◽  
Jun Jie Zeng ◽  
Yang Liao ◽  
Zheng Leng
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
High Strength Concrete ◽  
High Strength ◽  
Weak Zone ◽  
Strength Concrete ◽  
Bond Performance ◽  
Binder Ratio ◽  
Microstructural Morphology ◽  
Water To Binder Ratio

Concrete with a compressive strength of 100MPa was produced with metakaolin(MK), and the effect of MK replacement levels on compressive strength of concrete with a water to binder ratio of 0.25 was studied in this paper. XRD, microhardness tests, SEM and MIP were used to investigate the influences of MK on the phase composition, microhardness of interfacial transition zone(ITZ), microstructural morphology and pore structure of the high-strength concrete (HSC). The results showed that the incorporation of MK promoted the hydration process and decreased the amount of Ca(OH)2 crystals. Furthermore, MK increased the ITZ microhardness of HSC, enhanced the hydrates and improved the bond performance of aggregate and paste. The weak zone between aggregate and paste became almost disappeared when 10% MK was blended. Meanwhile, refinement of the concrete pore structure was obtained in the presence of MK. The improvement of strength and microstructure became more obvious as the MK replacement level increased to 15%.

scholarly journals A numerical model and validation of phase change material integrated thermoelectric radiant cooling panel

2019 ◽  
Vol 111 ◽  
pp. 01001
Author(s):  
Hansol Lim ◽  
Hye-Jin Cho ◽  
Seong-Yong Cheon ◽  
Soo-Jin Lee ◽  
Jae-Weon Jeong
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Numerical Model ◽  
Surface Temperature ◽  
Phase Change ◽  
Transfer Coefficient ◽  
Phase Change Material ◽  
Overall Heat Transfer Coefficient ◽  
Radiant Cooling ◽  
Change Material

A phase change material based radiant cooling panel with thermoelectric module (PCM-TERCP) is proposed in this study. It consists of two aluminium panels, and phase change materials (PCMs) sandwiched between the two panels. Thermoelectric modules (TEMs) are attached to one of the aluminium panels, and heat sinks are attached to the top side of TEMs. PCM-TERCP is a thermal energy storage concept equipment, in which TEMs freeze the PCM during the night whose melting temperature is 16○C. Therefore, the radiant cooling panel can maintain a surface temperature of 16◦C without the operation of TEM during the day. Furthermore, it is necessary to design the PCM-TERCP in a way that it can maintain the panel surface temperature during the targeted operating time. Therefore, the numerical model was developed using finite difference method to evaluate the thermal behaviour of PCM-TERCP. Experiments were also conducted to validate the performance of the developed model. Using the developed model, the possible operation time was investigated to determine the overall heat transfer coefficient required between radiant cooling panel and TEM. Consequently, the results showed that a overall heat transfer coefficient of 394 W/m2K is required to maintain the surface temperature between 16○C to 18○C for a 3 hours operation.

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