Modeling early age hydration reaction and predicting compressive strength of cement paste mixed with expansive additives

2019 ◽  
Vol 223 ◽  
pp. 994-1007 ◽  
Author(s):  
Nguyen Duc Van ◽  
Hyeonggil Choi ◽  
Yukio Hama
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Early Age ◽  
Hydration Reaction ◽  
Early Age Hydration

scholarly journals Early-Age Hydration Reaction and Strength Formation Mechanism of Solid Waste Silica Fume Modified Concrete

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5663
Author(s):  
Tao Luo ◽  
Cheng Hua ◽  
Qiang Sun ◽  
Liyun Tang ◽  
Yu Yi ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Solid Waste ◽  
Silica Fume ◽  
Morphological Characteristics ◽  
Early Age ◽  
Hydration Reaction ◽  
Compressive Strength Of Concrete ◽  
Early Age Hydration ◽  
Lf Nmr

Solid waste silica fume was used to replace fly ash by different ratios to study the early-age hydration reaction and strength formation mechanism of concrete. The change pattern of moisture content in different phases and micro morphological characteristics of concrete at early age were analyzed by low field nuclear magnetic resonance (LF-NMR) and scanning electron microscope (SEM). The results showed that the compressive strength of concrete was enhanced optimally when the replacement ratio of solid waste silica fume was 50%. The results of LF-NMR analysis showed that the water content of modified concrete increased with the increase of solid waste silica fume content. The compressive strength of concrete grew faster within the curing age of 7 d, which means the hydration process of concrete was also faster. The micro morphological characteristics obtained by SEM revealed that the concrete was densest internally when 50% fly ash was replaced by the solid waste silica fume, which was better than the other contents.

Hydration and Early Age Properties of Cement Pastes Modified with Cellulose Nanofibrils

2020 ◽  
pp. 036119812094599
Author(s):  
Hosain Haddad Kolour ◽  
Warda Ashraf ◽  
Eric N. Landis
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Cement Paste ◽  
Isothermal Calorimetry ◽  
Cellulose Nanofibrils ◽  
Autogenous Shrinkage ◽  
Early Age ◽  
Hydration Reaction ◽  
Cement Pastes ◽  
Degree Of Hydration

In this work, the effects of cellulose nanofibrils (CNFs) on workability, hydration reaction, microstructure, early age shrinkage, fracture properties, flexural strength, and compressive strength of cement paste were investigated. Six batches with variable CNF concentrations with the same water-to-cement (w/c) ratio (0.35) were tested. Flow table test showed a reduction in the workability as CNF dosage increased. Isothermal calorimetry (IC) tests showed that after 3 days, degree of hydration (DOH) improved up to 8% because of the addition of CNFs. Thermogravimetric analysis (TGA) tests at 7 and 28 days showed no significant changes in DOH for all pastes. After 7 days, mixture with 0.15% CNF resulted in up to 31% improvement in compressive strength. For 0.09% CNF addition, cement paste showed 26% increase in compressive strength after 28 days. Tests revealed that adding a small quantity of CNF (0.06%) along with entraining 0.05 extra water reduces autogenous shrinkage by 49% at a cement paste with w/c = 0.30. For interpreting the results, a tunnels, reservoirs, and bridges (TR&B) model is proposed. This model suggests that, as proposed by others, CNFs can modify microstructure by providing tunnels for transporting water to unhydrated cement grain. Because of their hydrophilicity, CNFs retain water and work as reservoirs (internal curing), which explains the improvement in properties at low w/c ratios. Significant increases in fracture energy (up to 60%) and flexural strength (up to 116%) suggest that CNFs are an effective toughening mechanism, acting as bridges that increase the energy required for crack propagation.

Controlling the early-age hydration heat release of cement paste for deep-water oil well cementing: A new composite designing approach

2021 ◽  
Vol 285 ◽  
pp. 122949
Author(s):  
Da-heng Wang ◽  
Xiao Yao ◽  
Tao Yang ◽  
Wen-rui Xiang ◽  
Ying-tao Feng ◽  
...  
Keyword(s):  
Heat Release ◽  
Cement Paste ◽  
Deep Water ◽  
Hydration Heat ◽  
Early Age ◽  
Oil Well ◽  
Early Age Hydration

scholarly journals CONTINUOUS MICROSTRUCTURAL CORRELATION OF SLAG/SUPERPLASTICIZER CEMENT PASTES BY HEAT AND IMPEDANCE METHODS VIA FRACTAL ANALYSIS

Fractals ◽  
2017 ◽  
Vol 25 (04) ◽  
pp. 1740003 ◽  
Author(s):  
S. W. TANG ◽  
R. J. CAI ◽  
Z. HE ◽  
X. H. CAI ◽  
H. Y. SHAO ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fractal Analysis ◽  
Setting Time ◽  
Blended Cement ◽  
Impedance Measurement ◽  
Heat Evolution ◽  
Early Age ◽  
Contact Impedance ◽  
Cement Pastes ◽  
Early Age Hydration

This paper presents a preliminary work to evaluate the influence of slag and superplasticizer on the early-age hydration of cement pastes by an innovative non-contact impedance measurement, heat evolution method, compressive strength and setting time tests. Besides, the cumulative pore volume obtained from modulus and phase of impedance in different hydration sections is taken to continuously correlate the cumulative heat releasing of cement pastes via the fractal analysis. Retarded phenomena and mechanism of hydration in cement pastes incorporated with slag and superplasticizer are studied, respectively. It is found that the compressive strength and setting time have a good linear relation with the slag amount in blended cement pastes.

scholarly journals Effects of graphene oxide on early-age hydration and electrical resistivity of Portland cement paste

2017 ◽  
Vol 136 ◽  
pp. 506-514 ◽  
Author(s):  
Wengui Li ◽  
Xiangyu Li ◽  
Shu Jian Chen ◽  
Yan Ming Liu ◽  
Wen Hui Duan ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Graphene Oxide ◽  
Portland Cement ◽  
Cement Paste ◽  
Early Age ◽  
Portland Cement Paste ◽  
Early Age Hydration

scholarly journals Experimental Study of the Mechanical Properties and Microstructures of Lightweight Toughness Cement-Based Composites

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3891 ◽  
Author(s):  
Wenhua Chen ◽  
Zhiyi Huang
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Cement Paste ◽  
Experimental Tests ◽  
Cement Matrix ◽  
Uniaxial Tensile ◽  
Hydration Reaction ◽  
Fiber Volume ◽  
Specific Strength ◽  
Long Span

The effects of cenospheres, an industrial waste residue, on the compressive strength, flexural strength, toughness, ductility, chemical component, microstructures, and micromechanics of lightweight toughness cement-based composites (LTCCs) by comprehensive experimental tests are explored in this paper. The results indicate that an increase in the amount of cenospheres leads to a decrease in the compressive and flexural strength of LTCCs. However, the specific strength of LTCCs increases with increasing cenosphere content. LTCCs containing 20% cenospheres and 1% fiber volume have the best toughness and ductility. Significant strain hardening occurs during the four-point bending and uniaxial tensile process. Furthermore, the incorporation of cenospheres promotes the hydration reaction of LTCCs due to its high pozzolanic activity. The LTCC cement paste has a low bonding strength to the fiber, which helps the fiber to be pulled out to produce greater bending deformation and tensile strain. The elastic modulus and hardness of the LTCC cement paste decrease linearly with increasing cenosphere content, which also causes the LTCC microstructure to become loose and more ettringite to generate. The weak interfacial transition zone between the cenospheres and the cement matrix is the important reason for the decreasing compressive strength of the LTCC. In conclusion, LTCC incorporating cenospheres is suitable for long-span steel deck pavements due to its light weight and excellent toughness. The successful application of cenospheres in engineering construction can save natural resources and contribute to sustainable development.

Mechanical Properties of Alite-Calcium Barium Sulphoaluminate Cement Concrete

2008 ◽  
Vol 400-402 ◽  
pp. 121-124
Author(s):  
Zong Hui Zhou ◽  
Ling Chao Lu ◽  
Xing Kai Gao ◽  
Xin Cheng
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Cement Paste ◽  
Early Age ◽  
Hardened Cement ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Hardened Cement Paste ◽  
Sulphoaluminate Cement

In this paper, preparation and mechanical properties of Alite-calcium barium sulphoaluminate (Alite-C2.75B1.25A3 ) cement concrete were studied. The results showed the compressive strength of Alite-C2.75B1.25A3 cement concrete was much higher than that of Portland cement concrete, especially the early-age compressive strength. The 24-hour compressive strength of Alite-C2.75B1.25A3 cement concrete could reach 22.81Mpa for w/c=0.45, 17.29Mpa for w/c=0.50 and 17.04Mpa for w/c=0.55 respectively. They were about 50 to 65 percent higher than those of Portland cement concrete. The 7-day compressive strength could reach about 80 to 90 percent of 28-day strength for Alite-C2.75B1.25A3 cement concrete. The 28-day strength could reach 55.85Mpa for w/c=0.45, 48.01Mpa for w/c=0.50 and 44.21Mpa for w/c=0.55 respectively. The results of SEM showed the interfaces between the hardened cement paste and aggregates in Alite-C2.75B1.25A3 cement concrete were more compact than those in Portland cement concrete. Distribution of particulate bulk was more uniformity and a majority of clinker particles was wrapped by hydrated gel in Alite-C2.75B1.25A3 concrete. And, the structure of Alite-C2.75B1.25A3 cement concrete was much more compact than that of Portland cement concrete.

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