Study on Preparation and the Setting Time of Magnesium Phosphate Cement

2014 ◽  
Vol 1049-1050 ◽  
pp. 251-255
Author(s):  
Run Qing Liu ◽  
Ding Qiang Chen ◽  
Tian Bo Hou
Keyword(s):  
Fly Ash ◽  
Orthogonal Experiment ◽  
Setting Time ◽  
Magnesium Phosphate ◽  
Mixture Ratio ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Orthogonal Analysis ◽  
Optimal Mixture Ratio

This paper mainly researched on preparation and the setting time of Magnesium Phosphate Cement (MPC). The method of orthogonal experiment was adapted to determine the best ratio of MPC, and change the content and types of the material according to the influence of various factors, so as to get the longer setting time of MPC. The results showed that, when the water cement ratio is 0.12, the factors significantly influencing the setting time is magnesium phosphorus ratio (M/P), fly ash and borax. The optimal mixture ratio was obtained through the orthogonal analysis, namely M/P is 3/1, borax content is 16%, and the amount of fly ash is 40%. When M/P is 1/1 and 2/2, borax content is not more than 22%, and the amount of fly ash was less than 60%, the longer setting time of MPC can be produced.

Study of Sleeper Concrete early Strength Based on Orthogonal Experiment

2013 ◽  
Vol 448-453 ◽  
pp. 1316-1320
Author(s):  
Hai Chao Wang ◽  
Ke Qiu ◽  
Shu Ling Gao
Keyword(s):  
Fly Ash ◽  
Design Method ◽  
Orthogonal Experiment ◽  
Orthogonal Design ◽  
Steam Curing ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Early Strength ◽  
The Difference ◽  
Railway Sleeper

Using orthogonal design method of four factors and three levels, make a mix ratio experiment on sleeper concrete of China's railway sleepers, used steam curing concrete early compressive strength (stripping strength) as evaluation index. Study on different experimental factors of water-cement ratio, sand ratio, fly ash and admixture differently influenced on the early strength of sleeper concrete and analyze the difference impact of each factor and level for the orthogonal experiment. The result shows that the admixture is the main factor for early strength of concrete, followed by fly ash, water-cement ratio and sand ratio. It can provide technical guidance for railway sleeper field and has practical value.

scholarly journals Experimental Study on Fluid Properties of Cement-Fly Ash Slurry Subjected to Multifactors

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Tian Huang ◽  
Feng Huang ◽  
Huifeng Zhou
Keyword(s):  
Fly Ash ◽  
Setting Time ◽  
Factors Affecting ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Initial Setting Time ◽  
Fluid Properties ◽  
Practical Engineering ◽  
Initial Setting ◽  
The Stability

There are many factors affecting the characteristics of cement-fly ash slurry in practical engineering. Thus, this paper studies the influence of multifactors on the fluid properties of cement-fly ash slurry based on water-cement ratio ( w / c ) (0.75, 1, 1.25, and 1.5), fly ash content (0%, 10%, 20%, 30%, 40%, and 50%) and temperature (20°C, 40°C, 60°C, and 80°C). The bleeding ratio, initial setting time, final setting time, and viscosity were analyzed under coupling conditions. It is found that the water-cement ratio ( w / c ) is the main factor that affects the rheological properties and bleeding rate of slurry. The temperature affects the stability of the slurry in terms that the bleeding ratio of the slurry decreases as the temperature increases. The addition of fly ash enhances the stability of the slurry under different temperature conditions.

scholarly journals Proportion optimization of grouting materials for roadways with soft surrounding mass

2020 ◽  
Author(s):  
Guorui Feng ◽  
Chenliang Hao ◽  
Pengfei Wang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Silicate ◽  
Raw Materials ◽  
Setting Time ◽  
Reducing Agent ◽  
Mixture Ratio ◽  
Cement Ratio ◽  
Performance Indexes ◽  
Grouting Material

Abstract Severe deformation and failure frequently occur in roadways with soft or weak surrounding rock and have greatly influenced safe and efficient mining of coal in many coal mines. Using portland cement, emery and fly ash as main raw materials, through laboratory tests, effect of water/binder ratio, cement/sand ratio, water/sodium silicate ratio, water reducing agent, fly ash/cement ratio and various performance indexes of grout of fluidity, viscosity, setting time, bleeding rate, compressive strength, concretion rate and various performance indexes were systematically analyzed. An optimized mixture ratio of the main raw materials added in the grouting material proportion was determined through uniform design method, an optimal mixture ratio was determined by regression analysis. The results show that: 1) The flow performance is significantly affected by change of sodium silicate and water reducer, the compressive strength of grouting material increases significantly with increase in emery content, and decreases significantly with increase in water reducer. 2) An optimized mixture ratio among water cement ratio, cement sand ratio, water/sodium silicate ratio, water reducing agent, fly ash/cement ratio in the grouting material is 0.75, 1.2, 8%, 3% and 0.18, respectively. Field test demonstrated that the material has better performance in reinforcing weak and broken rock mass.

Assessment of Hydration Degree of Cement in the Fly Ash-Cement Pastes Based on the Calcium Hydroxide Content

2014 ◽  
Vol 875-877 ◽  
pp. 177-182 ◽  
Author(s):  
Xiang Li ◽  
Hua Quan Yang ◽  
Ming Xia Li
Keyword(s):  
Fly Ash ◽  
Calcium Hydroxide ◽  
Cement Hydration ◽  
Ash Content ◽  
Content Increase ◽  
Hydration Degree ◽  
Equilibrium Calculation ◽  
Cement Pastes ◽  
Cement Ratio ◽  
Water Cement Ratio

The hydration degree of fly ash and the calcium hydroxide (CH) content were measured. Combined with the equilibrium calculation of cement hydration, a new method for assessment of the hydration degree of cement in the fly ash-cement (FC) pastes based on the CH content was developed. The results reveal that as the fly ash content increase, the hydration degree of fly ash and the CH content decrease gradually; at the same time, the hydration degree of cement increase. The hydration degree of cement in the FC pastes containing a high content of fly ash (more than 35%) at 360 days is as high as 80%, even some of which hydrates nearly completely. The effect of water-cement ratio to the hydration degree of cement in the FC pastes is far less distinct than that of the content of fly ash.

scholarly journals Evaluation of cementitious repair mortars modified with polymers

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668858 ◽  
Author(s):  
Tsai-Lung Weng
Keyword(s):  
Thermal Expansion ◽  
Bond Strength ◽  
Vinyl Acetate ◽  
Polyvinyl Acetate ◽  
Setting Time ◽  
Drying Shrinkage ◽  
Ethylene Vinyl Acetate ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Repair Mortars

The aim of this study was to evaluate the effects of added polymers on the properties of repair mortars. Two types of polymers, ethylene vinyl acetate and polyvinyl acetate–vinyl carboxylate, were used as a replacement for 3%, 5%, and 8% of the cement (by weight). All tests were conducted using two water–cement ratios of 0.5 and 0.6. The effectiveness of the repair materials was evaluated according to setting time, drying shrinkage, thermal expansion, compressive strength, and bond strength. Specimens containing polyvinyl acetate–vinyl carboxylate at a water–cement ratio of 0.5 presented the highest compressive and bond strength. Specimens containing ethylene vinyl acetate presented strength characteristics exceeding those of the control at 28 days. The drying shrinkage of polyvinyl acetate–vinyl carboxylate specimens was similar to that of the control. At a water–cement ratio of 0.5, the thermal expansion of polyvinyl acetate–vinyl carboxylate specimens was lower than that of ethylene vinyl acetate specimens; however, at a water–cement ratio of 0.6, the thermal expansion was independent of the type of polymer.

Experiment Research on Plastic Strength of Grouting Materials of Desulfurization Denitration Ash

2013 ◽  
Vol 275-277 ◽  
pp. 2093-2096
Author(s):  
Hong Hai Zhang ◽  
Ai Min Gong ◽  
Chun Yan Wang
Keyword(s):  
Fly Ash ◽  
Silicon Powder ◽  
Calculation Formula ◽  
Experiment Research ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Plastic Strength ◽  
Two Factors ◽  
Grouting Materials

Derived calculation formula of plastic strength, and used mortar consistency instrument to determine plastic strength. Through experiment, the fly ash and silicon powder that desulfurized or denitrated as grouting materials, its change rules of plastic strength were studid under different water cement ratio and different dosage conditions. Results shows that, between the two factors of water cement ratio and dosage, the water cement ratio affect significantly the plastic strength. The smaller the water cement ratio, the more obvious the increase of the plastic strength as time growth. Early plastic strength of silicon powder grouts is growing rapidly.

Evaluation of initial setting time due to superplasticizers

2017 ◽  
Vol 8 (2) ◽  
pp. 65
Author(s):  
Abhishek Singh ◽  
Shobha Ram ◽  
Alok Verma
Keyword(s):  
Water Content ◽  
Cement Paste ◽  
Setting Time ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Initial Setting Time ◽  
Initial Setting

This paper shows how polycarboxylate based superplasticizer affects the initial setting time of cement paste. Three superplasticizers are used in this study with different properties and aiming to determine the delay in initial setting time due to superplasticizer. Initial setting time is calculated as per IS: 4031-PART 5-1988 with different SP dosages (0.5%, 0.75%, 1.0% and 1.5% of weight of cement). Superplasticizer is an admixture which reduces the water-cement ratio or increase the workability at the same water content. This paper deals with the evaluation of initial setting time due to superplasticizers.

Research of Performance of Low Amount of Cement Manufactured-Sand Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 1200-1205
Author(s):  
Chun Hui Yu ◽  
Gu Hua Li ◽  
Jin Liang Gao ◽  
Qun Wei ◽  
Da Zhen Xu
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Grain Shape ◽  
Great Influence ◽  
Cementitious Materials ◽  
Natural Sand ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Manufactured Sand

Compared with natural sand, manufactured-sand is of small porosity, poor grain shape and graded, which impacts mixes workability and the properties after hardening. In Concrete, playing the role of retaining moisture water is mainly powder, including cement, powder in the sand and fly ash etc. The amount of powder has a great influence on the properties of concrete, especially on its workability. This paper mainly discusses the influence of amount of cement, cementitious materials, fly ash, water-cement ratio and other factors on the workability, compressive strength and shrinkage of concrete. The experiments show that, in the case of the low amount of cement, workability of the manufactured-sand concrete mixture, compressive strength and shrinkage deformation of test block all meet the actual requirements.

Research on the Variation of pH Value of the Ordinary Concrete and Fly Ash Concrete in the Carbonation Process

2011 ◽  
Vol 374-377 ◽  
pp. 1934-1937 ◽  
Author(s):  
Guang Zheng Qi ◽  
Di Tao Niu ◽  
Cheng Fang Yuan ◽  
Fu Zhen Duan
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Ph Value ◽  
Economic Benefits ◽  
Carbonation Depth ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Ordinary Concrete ◽  
Fly Ash Concrete ◽  
Carbonation Process

The accelerated carbonation test was carried out for the ordinary concrete and fly ash concrete. Influences of water-cement ratio, carbonation age and fly ash content on pH value were researched. The results show that carbonation depth, including incomplete carbonized zone, can be effectively reduced by reducing water-cement ratio. So lower water-cement ratio means high performance of resistance of carbonate. The use of fly ash can optimize concrete pore morphology, it’s beneficial for anti-carbonation. However, It disadvantageous to anti-carbonation because of less carbonation material. By taking appropriate mixture of fly ash we can not only enhance the anti-carbonation ability of concrete, but also reduce the use of cement to get well economic benefits.

Elimination of Negative Influence of Fluidized Bed Combustion Fly Ash on Viscosity of Cement Mix

2016 ◽  
Vol 865 ◽  
pp. 12-16 ◽  
Author(s):  
Martin Ťažký ◽  
Rudolf Hela
Keyword(s):  
Fly Ash ◽  
Fluidized Bed ◽  
Negative Impact ◽  
Negative Influence ◽  
Fluidized Bed Combustion ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Variable Chemical ◽  
Negative Feature ◽  
Cement Mixture

Use of fluidized bed combustion fly ash as an admixture for manufacture of cement based composite materials is not quite common now, however, there are real ways of utilizing its potential. The most important negative feature of this fly ash is its variable chemical composition, which supports formation of new forms growing within the structure with negative impact of durability of the composite material. The morphology of this type of fly ash is also not very favorable as it has negative influence on consistency. Fluidized bed combustion fly ash considerably deteriorates consistency of cement mixture, which results in higher water-cement ratio and consequently worsening of physico-mechanical and durability parameters of the whole composite. Therefore the question arises how to eliminate this negative influence on consistency without the necessity of increasing water cement ratio.

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