Early Strength Agent on the Properties of Reinforcement Materials Research

2013 ◽  
Vol 477-478 ◽  
pp. 936-940
Author(s):  
Chang Zheng Sun ◽  
Xiao Ping Zhang ◽  
Hai Nan Zhao ◽  
Qiang Gao
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Sodium Nitrite ◽  
Setting Time ◽  
Initial Flow ◽  
Final Setting Time ◽  
Reinforcement Material ◽  
Materials Research ◽  
Early Strength ◽  
Nitrite Content

In the trial, the author explores sodium nitrite, triethanolamine and sodium on fluidity initial and final setting time, flexural strength and compressive strength and other properties, of early strength reinforcement material. The results showed that, when sodium nitrite content is 0.2%, triethanolamine content is 0.05%, the dosage of sodium sulfate is 0.8%, final setting time for 58min, the initial flow greater than 320[mm], 30min flow greater than 280[mm], 2h compressive strength of 30[MPa], 1d bending greater than 10[MPa], 28d compressive strength greater than 90[MPa], on the early strength reinforcement, meet construction requirements.

Research on the Compound early Strength Agent to the Performance of Super High early Strength Grouting Material

2013 ◽  
Vol 477-478 ◽  
pp. 996-1001 ◽  
Author(s):  
Xiao Ping Zhang ◽  
Chang Zheng Sun ◽  
Tong Feng Zhao
Keyword(s):  
Compressive Strength ◽  
Sodium Sulfate ◽  
Setting Time ◽  
Cementitious Material ◽  
Final Setting Time ◽  
Grouting Material ◽  
Reinforcement Material ◽  
Reasonable Proportion ◽  
Strength Material ◽  
Early Strength

The effect of sodium sulfate, triethanolamine and early strength agent A on the early strength reinforcement material final setting time, flexural strength and compressive strength and structure were investigated. The results show that the composite of sodium sulfate, triethanolamine and early strength agent according to a reasonable proportion, the dosage of 0.35% -0.40% (in cementitious material quality), the final setting time of early strength material for 50 to 60 min, Initial fluidity over 320mm, 0.5h flow degree greater than 280mm, 1d bending greater than 12MPa and 28d compressive strength greater than 80MPa, meet the requirements.

Research on Sand Gradation to Ultra Strength Grouting Material Properties

2014 ◽  
Vol 507 ◽  
pp. 300-305
Author(s):  
Chang Zheng Sun ◽  
Xiao Ping Zhang ◽  
Hai Nan Zhao ◽  
Qiang Gao
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Material Properties ◽  
Setting Time ◽  
Fine Sand ◽  
Coarse Sand ◽  
Medium Sand ◽  
Final Setting Time ◽  
Grouting Material ◽  
Early Strength

The gradation of coarse sand, medium sand and fine sand on fluidity initial, final setting time, flexural strength, compressive strength, and other properties and structure, of ultra early strength grouting material, was explored. The quartz sand gradation of cement sand ratio 1.0 was systematically studied. The results showed that, the coarse sand, medium sand and fine sand mixed according to the reasonable distribution, when glue sand ratio was 1.0-1.5, ultra-early-strength grouting material, with final setting time for 50-60(min), the initial fluidity greater than 320(mm), 0.5h fluidity greater than 280(mm), 2h compressive strength of 35.6(MPa), 1d flexural strength greater than 13(MPa), 28d compressive strength over 93(MPa), achieved the free vibration.

The Influence of Alcohol Amine Admixtures on the Macroscopic Properties of Portland Cement Paste

2014 ◽  
Vol 525 ◽  
pp. 573-579
Author(s):  
Tian Yong Huang ◽  
Dong Min Wang ◽  
Ze Liu
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Cement Paste ◽  
Setting Time ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Cement Mortars ◽  
Macroscopic Properties ◽  
Initial Setting

It is studied the influence of triethanolamine (TEA), diethylenetriamine (DEA), Triisopropanolamine (TIPA), aminoethyl ethanolamine (AE), and polyvinyl alcohol ammonium phosphate (PAAP) at different dosages on the properties of fresh and hardened cement pastes and mortars prepared by Portland cement, including standard consistency water, setting time, the cement paste fluidity, and compressive and flexural strength. It is showed that the high polarity alcohol amine molecules exhibit strong chemical interactions with cement matrix, which are reflected in modified macroscopic properties of the cement system. All alcohol amine admixtures increased the standard consistency water and decreased cement paste fluidity of Portland cement. TEA significantly shortened the initial setting time and final setting time of Portland cement. On the other hand, TIPA, DEA, AE and PAAP extended the initial setting time of cement but shortened the cement final setting time. All alcohol amine admixtures except TIPA at 0.2 and 0.5 dosage increased the compressive and flexural strength of the Portland cement mortars at 3 days. Especially when the dosage of PAAP is 1, the compressive strength of the Portland cement mortars at 3 days is increased 10.5MPa. All alcohol amine admixtures except AE at 0.2 and 0.5 dosage increase the compressive and flexural strength of the Portland cement mortars at 28 days, Especially when the dosage of TIPA is 1, the compressive strength of the Portland cement mortars at 28 days is increased 8.8MPa.

scholarly journals Effect of Calcium Nitrate on the Properties of Portland–Limestone Cement-Based Concrete Cured at Low Temperature

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1611
Author(s):  
Gintautas Skripkiūnas ◽  
Asta Kičaitė ◽  
Harald Justnes ◽  
Ina Pundienė
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Setting Time ◽  
Calcium Nitrate ◽  
Curing Temperature ◽  
Hardened Concrete ◽  
Cement Pastes ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Early Strength

The effect of calcium nitrate (CN) dosages from 0 to 3% (of cement mass) on the properties of fresh cement paste rheology and hardening processes and on the strength of hardened concrete with two types of limestone-blended composite cements (CEM II A-LL 42.5 R and 42.5 N) at different initial (two-day) curing temperatures (−10 °C to +20 °C) is presented. The rheology results showed that a CN dosage up to 1.5% works as a plasticizing admixture, while higher amounts demonstrate the effect of increasing viscosity. At higher CN content, the viscosity growth in normal early strength (N type) cement pastes is much slower than in high early strength (R type) cement pastes. For both cement-type pastes, shortening the initial and final setting times is more effective when using 3% at +5 °C and 0 °C. At these temperatures, the use of 3% CN reduces the initial setting time for high early strength paste by 7.4 and 5.4 times and for normal early strength cement paste by 3.5 and 3.4 times when compared to a CN-free cement paste. The most efficient use of CN is achieved at −5 °C for compressive strength enlargement; a 1% CN dosage ensures the compressive strength of samples at a −5 °C initial curing temperature, with high early strength cement exceeding 3.5 MPa but being less than the required 3.5 MPa in samples with normal early strength cement.

Several Common Retarders on Performance of Ultra-Early-Strength Grouting Material

2013 ◽  
Vol 477-478 ◽  
pp. 931-935
Author(s):  
Chang Zheng Sun ◽  
Xiao Ping Zhang ◽  
Hai Nan Zhao ◽  
Qiang Gao
Keyword(s):  
Mechanical Strength ◽  
Setting Time ◽  
Strength Properties ◽  
Preliminary Screening ◽  
Final Setting Time ◽  
Grouting Material ◽  
Early Strength

To explore retarders on performance of ultra-early strength grouting material, Retarder, which are commonly used in the market after a preliminary screening, are further tested and analyzed for initial fluidity, setting time and mechanical strength properties of super early strength grouting material. The results show that: When borax content is 0.4%, the initial fluidity, final setting time, workability, mechanical strength are the best.

Behaviour of Calcium Alkali Orthophosphate Cements under Simulated Implantation Conditions

2008 ◽  
Vol 396-398 ◽  
pp. 213-216 ◽  
Author(s):  
Daniela Jörn ◽  
Renate Gildenhaar ◽  
Georg Berger ◽  
Michael Stiller ◽  
Christine Knabe
Keyword(s):  
Compressive Strength ◽  
Simulated Body Fluid ◽  
Clinical Application ◽  
Body Fluid ◽  
Setting Time ◽  
Great Decrease ◽  
Final Setting Time ◽  
Laboratory Conditions ◽  
Setting Times

The setting behaviour, the compressive strength and the porosity of four calcium alkali orthophosphate cements were examined under laboratory conditions (dry) and under conditions similar to those during clinical application (37°C, contact with body fluid). The results showed an increase of the setting times when specimens were covered with simulated body fluid. Especially, the final setting time (FHZ) was significantly higher for three of the four cements. Furthermore, when specimens were stored in SBF for 16h, an extensive decrease of the compressive strength was noted. The porosity was more than twice as high after 16h in SBF and this may be the cause for the great decrease of the compressive strength.

Effect of Metakaolin on Geopolymer Industry

2019 ◽  
pp. 49-70
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Reaction Mechanisms ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
Experimental Studies ◽  
Acid Attack ◽  
Repair Materials ◽  
Hardened State

This chapter discusses the effects of metakaolin (MK) on geopolymer mortar and concrete industries. The research topics of MK-based geopolymer cover reaction mechanisms and kinetics. This chapter aims at augmenting knowledge about enhancing mechanical properties of geopolymer mortars/concrete using MK. Specifically, this chapter presents literature studies as well as current experimental studies which delineate the effect of MK on fresh and hardened-state properties of geopolymer mortars (GPMs). Properties and characteristics of metakaolin are explained followed by properties of fresh MK mortars. Properties of hardened MK concrete and durability aspects of MK mortars are explained. Applications of MK-based geopolymers and metakaolin-based geopolymers as repair materials are also included in this chapter. The results of using MK-based GPMs revealed improved workability, enhanced setting time, increased density, higher compressive strength, flexural strength, and resistance against acid attack than conventional ordinary portland cement mortar/concrete.

scholarly journals Preparation of Portland Cement with Gold Ore Tailings

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Qiang Wang ◽  
Geng Yao ◽  
Xiangnan Zhu ◽  
Junxiang Wang ◽  
Peng Wu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Raw Materials ◽  
Setting Time ◽  
Hydration Product ◽  
Difficult Problem ◽  
Initial Setting Time ◽  
Gold Ore ◽  
Curing Age

The disposal of gold ore tailings (GTs) has been a very difficult problem for a long time. Thus, this study explored a new approach to the management of GTs by preparing Portland cement. Physical properties, reaction mechanisms, and hydration product types of cement prepared with GTs (C-GTs) and ordinary Portland cement (C-SS) were compared. X-ray diffraction (XRD), thermogravimetric (TG), and scanning electron microscope energy-dispersive spectroscopy (SEM-EDS) analysis techniques were used to study the mineralogical phases of the clinker and raw materials, hydration product types, and microtopography. The consistency, setting time, flexural strength and compressive strength values of the cement samples (C-GTs and C-SS), and burnability of the raw materials were also studied. The burnability analysis indicated that GTs provided a higher reactivity. The XRD results showed that the clinker phases of the C-GTs were C3S, C2S, C3A, and C4AF. The XRD, TG, and SEM-EDS results showed that the hydration products were flaky calcium hydroxide, rod-shaped ettringite, and granular C-S-H gels. Its compressive strength and flexural strength were, respectively, 30.4 MPa and 6.1 MPa at the curing age of 3 days and 59.1 MPa and 9.8 MPa at the curing age of 28 days, which were slightly higher than those of the C-SS. Furthermore, the results showed that the consistency, initial setting time, and final setting time for the two kinds of cement were similar, which further suggested that GTs could be used to prepare Portland cement.

scholarly journals Optimization and Hydration Mechanism of Composite Cementing Material for Paste Filling in Coal Mines

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Jinxiao Liu ◽  
Wenxin Li ◽  
Feng Zhang ◽  
Xinguo Zhang ◽  
Lianjun Chen ◽  
...  
Keyword(s):  
Early Stage ◽  
Uniform Design ◽  
Setting Time ◽  
Coal Mines ◽  
Hydration Products ◽  
Hydrated Calcium Silicate ◽  
Sulphoaluminate Cement ◽  
Final Setting Time ◽  
Early Strength ◽  
Cementing Material

The low early strength of materials for paste filling in mines caused by low early strength of composite cementing material has been a severe issue. In this study, the effects of sulphoaluminate cement and gypsum on strengths of composite cementing material were investigated experimentally by employing the constrained formulation uniform design. With the content of the sulphoaluminate cement below 14% and the content of the gypsum below 16%, the compressive strengths of composite cementing materials increased, especially early strength. However, the initial and final setting time does not meet the engineering requirements in this case. Optimization tests of composite additives demonstrated that H2BO3(0.3%) + Na2SO4(0.1%) and H2BO3(0.3%) + NaNO2(0.1%) were ideal setting retarding and early strengthening composite additives as they can both reduce the initial and final setting time and enhance compressive strengths of composite cementing material. Investigations by XRD and SEM revealed that the hydration products of composite cementing material were dominated by AFt (ettringite) at the early stage and by C-S-H (hydrated calcium silicate) gel + CH (calcium hydroxide) gel at the middle and late stages. The hydration products of ratio-optimized composite cementing material do not restrain each other due to the generation sequence. Instead, they grew interactively and were coupled, thus facilitating the growth of the hardened body. This study can provide references for optimization of composite cementing material for paste filling in coal mines.

Research on Multivariate Composite Super early Strength Grouting Materials

2013 ◽  
Vol 477-478 ◽  
pp. 990-995
Author(s):  
Xiao Ping Zhang ◽  
Chang Zheng Sun ◽  
Tong Feng Zhao
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Ordinary Portland Cement ◽  
High Alumina ◽  
Flow Ratio ◽  
Initial Flow ◽  
Growth Structure ◽  
Grouting Material ◽  
Early Strength ◽  
Grouting Materials

Super early strength high performance grouting material was produced using high alumina cement, ordinary portland cement, gypsum and silica fume. The different glue sand ratio and the cement sand ratio 1.0 mix microstructure were studied systematically. The results showed that the system with a variety of admixture using hingh mortar ratio can be prepared for the initial flow ratio greater than 325{mm},, 30min flow greater than 280{mm}, 2h compressive strength 34.80{MPa}, 24h bending over 13.82{MPa}, 28d compressive strength greater than 99.90{MPa}, 28d compressive strength greater than 56d compressive strength. The system of early SEM microstructures showed good crystal growth, structure compact.

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