scholarly journals Study on Formation Mechanism of Tobermorite in Cementitious Materials Using High Volume CaO-MgO-SiO2-Based Materials with Autoclave Curing

2017 ◽  
Vol 66 (3) ◽  
pp. 199-204
Author(s):  
Tomono KURIYAMA ◽  
Tsuyoshi SAITO ◽  
Kennosuke SATO ◽  
Tatsuhiko SAEKI
Keyword(s):  
Formation Mechanism ◽  
High Volume ◽  
Cementitious Materials ◽  
Autoclave Curing

scholarly journals Effect of Graphene Oxide Nanosheets on Physical Properties of Ultra-High-Performance Concrete with High Volume Supplementary Cementitious Materials

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1929 ◽  
Author(s):  
Yu-You Wu ◽  
Jing Zhang ◽  
Changjiang Liu ◽  
Zhoulian Zheng ◽  
Paul Lambert
Keyword(s):  
Graphene Oxide ◽  
Physical Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
High Volume ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Ultra High Performance Concrete ◽  
Steam Curing ◽  
Slump Flow

Nanomaterials have been increasingly employed for improving the mechanical properties and durability of ultra-high-performance concrete (UHPC) with high volume supplementary cementitious materials (SCMs). Recently, graphene oxide (GO) nanosheets have appeared as one of the most promising nanomaterials for enhancing the properties of cementitious composites. To date, a majority of studies have concentrated on cement pastes and mortars with fewer investigations on normal concrete, ultra-high strength concrete, and ultra-high-performance cement-based composites with a high volume of cement content. The studies of UHPC with high volume SCMs have not yet been widely investigated. This paper presents an experimental investigation into the mini slump flow and physical properties of such a UHPC containing GO nanosheets at additions from 0.00 to 0.05% by weight of cement and a water–cement ratio of 0.16. The study demonstrates that the mini slump flow gradually decreases with increasing GO nanosheet content. The results also confirm that the optimal content of GO nanosheets under standard curing and under steam curing is 0.02% and 0.04%, respectively, and the corresponding compressive and flexural strengths are significantly improved, establishing a fundamental step toward developing a cost-effective and environmentally friendly UHPC for more sustainable infrastructure.

scholarly journals Sustainable low-carbon binders and concretes

2020 ◽  
Vol 166 ◽  
pp. 06007
Author(s):  
Myroslav Sanytsky ◽  
Tetiana Kropyvnytska ◽  
Stanislav Fic ◽  
Hanna Ivashchyshyn
Keyword(s):  
Activity Index ◽  
Chemical Properties ◽  
High Volume ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Cement Matrix ◽  
Low Carbon ◽  
Blended Cements ◽  
Physical And Chemical

Sustainable development depends on a consistency of interests, social, ecological and economic, and that the interests are evaluated in a balanced manner. In order to reduce CO2 emissions, the conception of decreasing clinker factor and increasing the role of supplementary cementitious materials (SCMs) in the cementitious materials has high economical and environmental efficiency. The performance of clinkerefficient blended cements with supplementary cementitious materials were examined. The influence of superfine zeolite with increased surface energy on the physical and chemical properties of low-carbon blended cements is shown. Increasing the dispersion of cementitious materials contributes to the growth of their strength activity index due to compaction of cement matrix and pozzolanic reactions in unclincker part. In consequence of the early structure formation and the directed formation of the microstructure of the cement matrix is solving the problem of obtaining clinker-efficient concretes. Shown that low-carbon blended cements with high volume of SCMs are suitable, in principle, for producing structural concretes.

Compressive strength and hydration of high-volume wet-grinded coal fly ash cementitious materials

2019 ◽  
Vol 206 ◽  
pp. 248-260 ◽  
Author(s):  
Hongbo Tan ◽  
Kangjun Nie ◽  
Xingyang He ◽  
Xiufeng Deng ◽  
Xun Zhang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Fly Ash ◽  
High Volume ◽  
Cementitious Materials

scholarly journals Effects of Wet Separated and High Speed Milling Fly Ash Added in High Volume to Cementitious Materials

2020 ◽  
Author(s):  
Usman Haider ◽  
Asif Ali ◽  
Zdeněk Bittnar ◽  
Muhammad Humayon ◽  
Jan Valentin
Keyword(s):  
Fly Ash ◽  
Brown Coal ◽  
Maximum Concentration ◽  
High Speed ◽  
Autogenous Shrinkage ◽  
High Volume ◽  
Cementitious Materials ◽  
Mean Value ◽  
Milling Process ◽  
High Speed Milling

In this research high speed milling was carried out on particles of brown coal raw fly ash, on second layer, and on third layer particles obtained from wet separation of brown coal raw fly ash. Due to milling process, median particle size d50 of raw fly ash, second layer, and third layer reduced by 46 %, 23 %, and 77 %, densities reduced by 11 %, 17 %, and 8 % respectively. Due to milling process, formation of agglomerations was observed, the standard deviation of the chemical composition of each element from the mean value reduced. After milling, high volume cementitious paste mixes were prepared with 60 % cement replacement. Due to the milling process the increase in compressive strength at 28 and 90 days was observed for raw fly ash is 59 % and 16 %, for second layer is 12 % and 15 %, for third layer and milled third layer is 78 % and 75 %. Flexural strength testing showed that due to the milling process the deflections at maximum loads have reduced considerably leading to brittle behavior of milled cementitious specimens. The testing for Mercury Intrusion Porosimetry showed that the cementitious specimens of third layer have maximum concentration of large capillary pores between 0.05 and 10 µm, whereas, all others have maximum concentration of medium capillary pores between 0.01 and 0.05 µm. Autogenous shrinkage of cementitious specimens was measured for first sixteen hours after mixing which showed that the second layer particles have the least shrinkage as compared to all other specimens.

EFFECT OF ACCELERATED CURING ON ABRASION OF HIGH VOLUME SUPPLEMENTARY CEMENTITIOUS MATERIAL SELF CONSOLIDATING CONCRETE

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Hayder H. Alghazali ◽  
John J. Myers
Keyword(s):  
Prestressed Concrete ◽  
Abrasion Resistance ◽  
High Volume ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Supplementary Cementitious Materials ◽  
Supplementary Cementitious Material ◽  
Self Consolidating Concrete ◽  
Accelerated Curing ◽  
Precast Prestressed Concrete

Sustainability of precast/prestressed concrete plant can be promoted by using supplementary cementitious material and that significantly reduces the embodied energy of precast/ prestressed concrete products. Usually, up to 25% of the cement can be replaced with supplementary cementitious materials (SCM). Increasing the level of replacement to exceed 25% is considered to be High-Volume SCM. Appropriate testing should be conducted to ensure desired performance of the concrete. This context reports the results of an experimental investigation of effect of accelerated curing on abrasion resistance of High Volume Supplementary Cementitious Material – Self Consolidating Concrete (HVSCM-SCC). Different mixes proportion with supplementary cementitious materials such as Fly Ash, Micro Silica, and lime (Up to 75% of cement replacement) were tested. Rheological properties of the HVSCM-SCC were measured. Mechanical properties at different ages 1, 3, 7, 28, 56, and 90 days were monitored. To investigate the abrasion resistance, 12 x 12 x 3.5 in specimens at age of 28, 56, and 90 days were conducted. The results of abrasion resistance of HVSCM-SCC were compared to the same mixes cured in the moist room. The result showed that the accelerated curing has a significant influence on abrasion resistance of concrete at early ages.

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