scholarly journals Evaluation of the Mechanical Properties of Normal Concrete Containing Nano-MgO under Freeze–Thaw Conditions by Evolutionary Intelligence

2021 ◽  
Vol 11 (6) ◽  
pp. 2529
Author(s):  
Mehdi Yazdchi ◽  
Ali Foroughi Asl ◽  
Siamak Talatahari ◽  
Amir H. Gandomi
Keyword(s):  
Mechanical Properties ◽  
Gene Expression Programming ◽  
Training Process ◽  
Normal Concrete ◽  
Acceptable Accuracy ◽  
Freeze And Thaw ◽  
Binder Ratio ◽  
Prediction Of Mechanical Properties ◽  
Water To Binder Ratio ◽  
Evolutionary Intelligence

In this research, different amounts of nano-MgO were added to normal concrete samples, and the effect of these particles on the durability of the samples under freeze and thaw conditions was investigated. The compressive and tensile strength as well as the permeability of concrete containing nanoparticles were measured and compared to those of plain samples (without nanoparticles). The age of concrete samples, percentage of nanoparticles, and water-to-binder ratio are the variables of the current research. Based on the results, the addition of 1% nano-MgO to the normal concrete with a water-to-binder ratio of 0.44 can reduce the permeability up to 63% and improve the compressive and tensile strengths by 9.12% and 10.6%, respectively. Gene Expression Programming (GEP) is applied, and three formulations are derived for the prediction of mechanical properties of concrete containing nano-MgO. In this method, 80% of the dataset is used randomly for the training process and 20% is utilized for testing the formulation. The results obtained by GEP showed acceptable accuracy.

scholarly journals Bond Strength between Glass Fiber Fabrics and Low Water-to-Binder Ratio Mortar: Experimental Characterization

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Daniel Bohling ◽  
Andrzej Cwirzen ◽  
Karin Habermehl-Cwirzen
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Bond Strength ◽  
Glass Fiber ◽  
Penetration Depth ◽  
Pullout Strength ◽  
Lap Shear Strength ◽  
Lap Shear ◽  
Binder Ratio ◽  
Water To Binder Ratio

Full utilization of mechanical properties of glass fiber fabric-reinforced cement composites is very limited due to a low bond strength between fibers and the binder matrix. An experimental setup was developed and evaluated to correlate the mortar penetration depth with several key parameters. The studied parameters included fresh mortar properties, compressive and flexural strengths of mortar, the fabric/mortar bond strength, fabric pullout strength, and a single-lap shear strength. Results showed that an average penetration of mortar did not exceed 100 µm even at a higher water-to-binder ratio. The maximum particle size of the used fillers should be below an average spacing of single glass fibers, which in this case was less than 20 µm to avoid the sieving effect, preventing effective penetration. The pullout strength was strongly affected by the penetration depth, while the single-lap shear strength was also additionally affected by the mechanical properties of the mortar.

Microscopic Analysis and Study of High-Performance Seawater All-Coral Concrete

2019 ◽  
Vol 815 ◽  
pp. 216-222
Author(s):  
Chao Chen ◽  
Jin Ming Liu ◽  
Yang Yang ◽  
Zhi Guo Guo
Keyword(s):  
Mechanical Properties ◽  
Natural Environment ◽  
High Performance ◽  
Work Performance ◽  
Room Temperature ◽  
Microscopic Analysis ◽  
Internal Curing ◽  
Mix Design ◽  
Binder Ratio ◽  
Water To Binder Ratio

The ocean islands are far from inland and the concrete sandstone aggregates are scarce. In this paper, high-performance seawater all-coral concrete was developed by seawater mixing and room temperature maintenance design, and by optimizing the water-to-binder ratio, regulating internal curing, changing auxiliary cementing materials and blending ratio, incorporating expansion agent, adjusting fiber blending, etc. Combined with the consideration of work performance and mechanical properties, the concrete self-shrinkage is adjusted to further optimize the mix design. The mechanical properties of the optimized high-performance seawater all-coral concrete were studied, and the relevant durability tests were carried out according to the natural environment characteristics of the island. This is of great significance to the construction of island projects, repair and construction, and construction of protective projects [1].

Influence of water to binder ratio on mechanical properties of blended cements with brick powder waste

2019 ◽  
Author(s):  
Deák György ◽  
Ana Maria Panait ◽  
Andreea Mihaela Moncea ◽  
Diana Florina Dumitru ◽  
Madalina Boboc ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Blended Cements ◽  
Brick Powder ◽  
Influence Of Water ◽  
Binder Ratio ◽  
Water To Binder Ratio

scholarly journals Effects of CNT Dosages in Cement Composites on the Mechanical Properties and Hydration Reaction with Low Water-to-Binder Ratio

2019 ◽  
Vol 9 (21) ◽  
pp. 4630 ◽  
Author(s):  
Sang-Hwa Jung ◽  
Sungwoo Oh ◽  
Sung-Wook Kim ◽  
Jae-Heum Moon
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Construction Material ◽  
Isothermal Calorimetry ◽  
Strength Development ◽  
Hydration Reaction ◽  
Cement Composites ◽  
Gravimetric Analysis ◽  
Binder Ratio ◽  
Water To Binder Ratio

This study aimed to investigate the potential use of carbon nanotubes (CNTs), which are an innovative construction material preferred by many researchers. Long-term microstructure enhancement and on-site application are major reasons to conduct research on CNT-cement composites; thus, a study on mechanical properties as well as the thermal conductivity of CNT-cement composites was carried out. As the CNT content increased, the thermal conductivity of CNT-cement composites was also enhanced. In addition, a couple of microstructure analyses such as isothermal calorimetry, thermal gravimetric analysis and SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy) for observing hydration reaction rate and types of hydration products were conducted to establish the advantage of CNT use in cement composites. Strength development of CNT-cement composites at early ages was slow, although eventually CNTs containing water developed equivalent level of strengths at last as internal curing effects.

scholarly journals Effect of Fly Ash on Some Properties of Reactive Powder Concrete

2021 ◽  
Vol 27 (11) ◽  
pp. 32-46
Author(s):  
Zahraa F Muhsin ◽  
Nada Mahdi Fawzi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Industrial Wastes ◽  
Experimental Program ◽  
Reactive Powder Concrete ◽  
Binder Ratio ◽  
Reactive Powder ◽  
Water To Binder Ratio

To achieve sustainability in the field of civil engineering, there has become a great interest in developing reactive powder concrete RPC through the use of environmentally friendly materials to reduce the release of CO2 gas produced from cement factories as well as contribute to the recycling of industrial wastes that have a great impact on environmental pollution. In this study, reactive powder concrete was prepared using total binder content of 800 kg/m3, water to binder ratio (0.275), and micro steel fibers  1% by volume of concrete. The experimental program included replacing fly ash with (8, 12, 16) % by cement weight to find the optimal ratio, which achieved the best mechanical properties of (RPC) at 7, 28, and 90 days with standard curing. Some mechanical properties of reactive powder concrete (flow, compressive strength, tensile strength, and density) were verified. The results at 28 days showed that the compressive strength (96.5) Mpa, tensile strength (9.38) Mpa, and density (2395 kg/m3). The results showed that the percentage of replacement of 8% of fly ash with cement is the optimal percentage, which achieved the highest resistance compared to the others. The results also indicated that it is possible to develop RPC using fly ash with a high withstand stress, tensile strength, and density.

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