Influence of Stearic Acid on Portland Cement Performance as Grinding Aids

2011 ◽  
Vol 374-377 ◽  
pp. 1244-1248 ◽  
Author(s):  
Hao Xin Li ◽  
Jian Sen Yang ◽  
Hong Bo Zhu
Keyword(s):  
Compressive Strength ◽  
Stearic Acid ◽  
Portland Cement ◽  
Specific Surface ◽  
Cement Paste ◽  
Heat Liberation ◽  
Hydration Heat ◽  
Grinding Aids ◽  
Cement Grinding ◽  
Production Composition

Different contents of stearic acid were added to mixtures, and the influences of stearic acid as grinding aids on portland cement performances, including specific surface, compressive strength, hydration heat, Ca(OH)2 (CH) content, C-S-H gel and ettringite (AFT) content were discussed in this paper. The results show that the addition of small amount of stearic acid is enough, and excessive addition of stearic acid is not a good matter to cement grinding. Adding a small amount of stearic acid, not only don’t improve the compressive strength, but also lower the compressive strength significantly. Although the specific surface of samples with 0.1% stearic acid is lower than that of the samples with 0.025% stearic acid and reference, the compressive strength appears of higher than others. Addition of stearic acid affects not only on the rate of heat liberation, but also the hydration heat significantly. The addition of stearic acid has uncommonly impact on the content of CH, C-S-H and AFT in cement paste at 3 days, 7days and 28 days hydration age, the samples with 0.1% stearic acid has higher content of CH, C-S-H and AFT than others, and lower conversion content of AFT from 3days to 7days and 7days to 28 days. This can explain why the cement with 0.1% stearic acid is provided with the higher compressive strength than others, from the perspective of hydration production composition.

scholarly journals ANALYSIS OF PROPERTIES OF CONCRETE USING MANUFACTURE SAND AS FINE AGGRIGATES

2017 ◽  
Vol 5 (11) ◽  
pp. 338-342
Author(s):  
Vishal Gadgihalli ◽  
Ramya ◽  
Babitha Rani ◽  
Raghavendra Prasad HavanjeDinakar ◽  
Lohith
Keyword(s):  
Compressive Strength ◽  
Soil Erosion ◽  
Portland Cement ◽  
Cement Paste ◽  
Chemical Reaction ◽  
Paper Analysis ◽  
Exothermal Reaction ◽  
Normal Concrete ◽  
River Sand

Aggregate in concrete acts as structural filler, these place a crucial than simple statement implies it is the material that the cement paste coats and blind together. Now a day’s using river sand is prohibited by government, as these cause soil erosion. In this paper analysis of properties of concrete using manufacture sand as course aggregate is studied and verified the strength of concrete and temperature emitted due to chemical reaction to the normal Portland cement. Using manufacture sand as course aggregate the temperature emitted due to exothermal reaction of concrete has reduced. Although the compressive strength of the concrete has reduced compared to normal concrete where no admixtures were used to enhance the properties of concrete.

scholarly journals Comparison of Effects of Sodium Bicarbonate and Sodium Carbonate on the Hydration and Properties of Portland Cement Paste

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1033 ◽  
Author(s):  
Yuli Wang ◽  
Fengxia He ◽  
Junjie Wang ◽  
Qianku Hu
Keyword(s):  
Compressive Strength ◽  
Sodium Bicarbonate ◽  
Portland Cement ◽  
Cement Paste ◽  
Sodium Carbonate ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
Sprayed Concrete ◽  
Final Setting Time ◽  
Portland Cement Paste

Carbonates and bicarbonates are two groups of accelerators which can be used in sprayed concrete. In this study, the effects of the two accelerators sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) (0%, 1%, 2%, 3%, and 4% by weight of ordinary Portland cement OPC) on the properties of OPC paste were compared. The results show that both of them could accelerate the initial and final setting time of OPC paste, but the effect of the two accelerators on the compressive strength were different. After 1 day, sodium bicarbonate at 3% had the highest strength while sodium carbonate at 1% had the highest strength. After 7 days, both of the two accelerators at 1% had the highest compressive strength. After 28 days, the compressive strength decreased with the increase of the two. The improved strength at 1 and 7 days was caused by the accelerated formation of ettringite and the formation of CaCO3 through the reactions between the two with portlandite. The decrease of strength was caused by the Na+ could reduce the adhesion between C-S-H gel by replacing the Ca2+. NaHCO3 was found be a better accelerator than Na2CO3.

scholarly journals Pengaruh Air Laut sebagai Air Pencampur dan Air Perawatan pada Karakteristik Pasta Semen dan Mortar

2018 ◽  
Vol 5 (1) ◽  
pp. 28
Author(s):  
Adiwijaya Ali ◽  
Irka Tangke Datu
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cement Paste ◽  
Tap Water ◽  
Fine Aggregate ◽  
Curing Conditions ◽  
Composite Cement ◽  
Water Characteristics ◽  
Water Curing ◽  
Mixing Water

The goal of this research is to investigate the influence of seawater as mixing water and curing water on characteristics of cement paste and mortar. Research was conducted with making mixtures of cement paste and mortar using two kind of cement, Portland Composite Cement (PCC) and Pozzolana Portland Cement (PPC) with seawater as mixing water. Characteristics of fine aggregate and characteristics of cement paste with seawater mixing were investigated. Furthermore, 144 cube mortar specimens in size of 5 cm x 5 cm x 5 cm in four series mortar mixtures were casted according with SNI 03-6825-2002. At 24 hours after specimens were casted, cube mortar specimens were cured in tap water curing (TC), seawater curing (SC) and air curing (AC). After achievement at certain curing day of 3, 7, 14 and 28 days, cube mortar samples were tested in compressive strength. Results concluded that seawater mixing improves compressive strength of mortar up to 28 days in all curing conditions, TC, SC and AC. Moreover, strength of mortar is not affected by type of curing water, tap water or seawater.

Using High Temperature for Improve Compressive Strength of Ordinary Portland Cement Paste (OPC) – A New Approach

2014 ◽  
Vol 894 ◽  
pp. 70-76
Author(s):  
Abdoullah Namdar ◽  
Fadzil Mat Yahaya ◽  
Mashita Mohd Yusoff
Keyword(s):  
Surface Roughness ◽  
Compressive Strength ◽  
Portland Cement ◽  
Cement Paste ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
New Approach ◽  
Force Microscopy ◽  
Atomic Force ◽  
Portland Cement Paste

Cement paste was replaced with kaolin-bentonite. The specimens were exposed to elevated temperature for 3 hours in a ceramic furnace and cooled down to room temperature. After cooling, the effect of kaolin-bentonite (particles sized of < 45μm) on hydration, rehydration, surface roughness and compressive strength of ordinary Portland cement (OPC) paste were investigated. Atomic Force Microscopy (AFM) was used to study surface roughness of OPC paste-additive mixture. The application of fire on OPC paste was analyzed. The results showed imposed heat (500 oC for 3 hours) accelerates the hydration process of OPC, and reduces setting time. Increased heat to 1000 oC, leads to zero compressive strength of specimens, the compressive strength of OPC continuously reduces after specimen has fully cooled down. A method for recovery of compressive strength of OPC after offing fire has been suggested. The method of offing fire has important effects on the compressive strength of concrete. The best results for specimen content are cement-kaolin-bentonite paste, exposure to 500 o C, after 90 days of curing, and cooling down in water. In this case the compressive strength has been increased around 60 % compared to not using additive and not exposing to heat.

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.

scholarly journals Mechanical Activation of Granulated Copper Slag and Its Influence on Hydration Heat and Compressive Strength of Blended Cement

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 772 ◽  
Author(s):  
Yan Feng ◽  
Jakob Kero ◽  
Qixing Yang ◽  
Qiusong Chen ◽  
Fredrik Engström ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Specific Surface ◽  
Mechanical Activation ◽  
Surface Area ◽  
Specific Surface Area ◽  
Milling Time ◽  
Copper Slag ◽  
Pozzolanic Activity ◽  
Hydration Heat ◽  
Strength Development

Mechanical activation of granulated copper slag (GCS) is carried out in the present study for the purposes of enhancing pozzolanic activity for the GCS. A vibration mill mills the GCS for 1, 2, and 3 h to produce samples with specific surface area of 0.67, 1.03 and 1.37 m2/g, respectively. The samples are used to replace 30% cement (PC) to get 3 PC-GCS binders. The hydration heat and compressive strength are measured for the binders and derivative thermogravimetric /thermogravimetric analysis (DTG/TGA), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) are used to characterize the paste samples. It is shown that cumulative heat and compressive strength at different ages of hydration and curing, respectively, are higher for the binders blending the GCS milled for a longer time. The compressive strength after 90 d of curing for the binder with the longest milling time reaches 35.7 MPa, which is higher than the strength of other binders and close to the strength value of 39.3 MPa obtained by the PC pastes. The percentage of fixed lime by the binder pastes at 28 days is correlated with the degree of pozzolanic reaction and strength development. The percentage is higher for the binder blending the GCS with longer milling time and higher specific surface area. The pastes with binders blending the GCS of specific surface area of 0.67 and 1.37 m2/g fix lime of 15.20 and 21.15%, respectively. These results together with results from X-ray diffraction (XRD), FTIR, and SEM investigations demonstrate that the mechanical activation via vibratory milling is an effective method to enhance the pozzolanic activity and the extent for cement substitution by the GCS as a suitable supplementary cementitious material (SCM).

Positive effects of novel nano-zirconia on flexural and compressive strength of Portland cement paste

Polyhedron ◽  
2020 ◽  
Vol 177 ◽  
pp. 114317 ◽  
Author(s):  
Behnam Behnia ◽  
Ali Aali Anvari ◽  
Hossein Safardoust-Hojaghan ◽  
Masoud Salavati-Niasari
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cement Paste ◽  
Positive Effects ◽  
Portland Cement Paste

scholarly journals Effect of Delaminated MXene (Ti3C2) on the Performance of Cement Paste

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jianping Zhu ◽  
Genshen Li ◽  
Chunhua Feng ◽  
Libo Wang ◽  
Wenyan Zhang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cement Paste ◽  
Cement Hydration ◽  
Hydration Heat ◽  
Hydration Process ◽  
Cement Matrix ◽  
Cement Composites ◽  
Hydrated Cement ◽  
Hydration Products

Delaminated MXene was incorporated into cement to improve the properties of cement composites, and its effects on the hydration process, microstructures, and mechanical properties were investigated, respectively. The investigation results showed that delaminated MXene was well-dispersed in the cement matrix and significantly reinforced the compressive strength of cement, especially when the addition is 0.01 wt%. Meanwhile, the total hydration heat of cement hydration and the quantity of hydration products were increased with the addition of delaminated MXene. In addition, the formation of HD C-S-H gel was promoted, and the microstructure of hydrated cement became more compact.

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