Influence of Mixing Method of Mineral Admixture on Performance of Recycled Concrete

2012 ◽  
Vol 598 ◽  
pp. 612-617 ◽  
Author(s):  
Ying Li ◽  
Da Hu Dai
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Recycled Concrete ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Mixing Method

In order to improve the microstructure of recycled concrete, the mineral admixtures were mixed into recycled concrete by different mixing method in this paper. It is demonstrated that the early compressive strength of recycled concrete decreased when mixed by fly ash only, but its later strength increasing rate is higher than recycled concrete without fly ash. When mixed fly ash and silica fume in the recycled concrete, the compressive strength of recycled concrete with fly ash and silica fume is higher than the strength of recycled concrete with fly ash only, and its microstructure tend to be dense.

Study on the Durability of Concrete with Mineral Admixtures to Sulfate Attack by Wet-Dry Cycle Method

2011 ◽  
Vol 295-297 ◽  
pp. 165-169
Author(s):  
Guan Guo Liu ◽  
Jing Ming ◽  
Xiong Wen Zhang ◽  
Ai Bin Ma
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sulfate Attack ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Change Environment ◽  
Physical Mechanisms ◽  
Chemical Attack ◽  
Tidal Area

Sulfate attack is one of several chemical and physical mechanisms of concrete deterioration. In actual situation, concrete structures always suffer from the coupled effects of multifactor such as wet-dry cycle and sulfate attack when exposed to tidal area or groundwater level change environment. Partial replacement of cement with mineral admixture is one of the efficient methods for improving concrete resistance against sulfate attack. In this regard, the resistance of concrete with fly ash and slag to sulfate attack was investigated by wet-dry cycle method. The degree of sulfate attack on specimens after different cycles was observed using scanning electron microscopy. The results of compressive strength and percentage of compressive strength evolution factor at various cycling times show an increase in the sulfate resistance of concrete with 60% of fly ash and slag than that only with 40% fly ash. The microstructural study indicates that the primary cause of deterioration of concrete under wet-dry cycle condition is swelling of the sulfate crystal rather chemical attack.

A Research on the Anti-Sulfate Corrosion Effects of the Concrete Mixed with Complex Multi-Mineral Admixture

2011 ◽  
Vol 71-78 ◽  
pp. 755-759
Author(s):  
Ying Tang ◽  
Guo An Wang
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Significant Influence ◽  
Ash Content ◽  
Performance Characteristics ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Corrosion Effect ◽  
Slag Content

This paper is focused on the method for improving capability of anti-sulfate corrosion of concrete. Based on the performance characteristics of mineral admixture, propose a method that mixing concrete with complex multi-mineral admixture to improve the effect of anti-sulfate corrosion. Finally, the ability of anti-sulfate corrosion and anti-dry-wet cycle, in different case, is studied and compared. The results show that concrete mixed with complex multi-mineral admixture is advantageous to improve the anti-sulfate corrosion effects of the concrete. The proportion of mineral admixtures has significant influence on the anti-sulfate corrosion effect. As the silica fume and slag content increased, the fly ash content decreased, the ability of anti-sulfate corrosion enhanced.

Effect of steel slag powder, fly ash, and silica fume on the mechanical properties and durability of cement mortar

2019 ◽  
Vol 9 (9) ◽  
pp. 1049-1054
Author(s):  
Yunxia Lun ◽  
Fangfang Zheng
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cement Mortar ◽  
Steel Slag ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Slag Powder ◽  
Steel Slag Powder

This study is aimed at exploring the effect of steel slag powder (SSP), fly ash (FA), and silica fume (SF) on the mechanical properties and durability of cement mortar. SSP, SF, and FA were used as partial replacement of the Ordinary Portland cement (OPC). It was showed that the compressive and bending strength of steel slag powder were slightly lower than that of OPC. An increase in the SSP content caused a decrease in strength. However, the growth rate of compressive strength of SSP2 (20% replacement by the weight of OPC) at the curing ages of 90 days was about 8% higher than that of OPC, and the durability of SSP2 was better than that of OPC. The combination of mineral admixtures improved the later strength, water impermeability, and sulfate resistance compared with OPC and SSP2. The compressive strength of SSPFA (SSP and SF) at 90 days reached 70.3 MPa. The results of X-ray diffraction patterns and scanning electron microscopy indicated that SSP played a synergistic role with FA or SF to improve the performance of cement mortar.

Influence of Compounded Mineral Admixtures on Shrinkage and Early-Age Cracking Behaviors of Concrete

2012 ◽  
Vol 450-451 ◽  
pp. 738-742
Author(s):  
Xue Fang Wang ◽  
Jian Lan Zheng
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Synergistic Effect ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Early Age ◽  
Volume Stability ◽  
Furnace Slag

Influence of compounded mineral admixtures on shrinkage and early-age cracking behaviors of concrete was studied, based on the fellow factors: fly ash to blast furnace slag(denoted as BSF) ratio, fly ash-metakaolin ratio, BSF-silica fume ratio. Research shows that the Pozzolanic admixtures compounded with cementitious admixtures have complementary and synergistic effect for hydration progress of concrete, which can enhance the volume stability and cracking behaviors of concrete. However, the pozzolanic admixture compounded with other pozzolanic admixture, two pozzolanic admixtures will grab Ca(OH)2 resource. And then if the dosage of mineral admixture is higher, the compounding will result to decrease the volume stability and cracking behaviors of concrete.

Influence of Mineral Admixtures on Mortar Brittleness

2010 ◽  
Vol 168-170 ◽  
pp. 281-285
Author(s):  
Ben Lin Xiao ◽  
Li Hua Li ◽  
Hui Ming Tang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mineral Admixtures ◽  
Test Results ◽  
Paper Test

The influence of mineral admixtures on mortar brittleness is analysed in this paper. Test results show that the mortar brittleness increases with the increasing of compressive strength and the passage of age. When the content of binding materials rises, the compressive strength also increases, but the brittleness decreases at the same time. The more the content of fly ash is, the more the brittleness falls. Silica fume added can not only enhance compressive strength but also reduce brittleness of the mortar. MgO added can cut down the brittleness, but can reduce the compressive strength a little at the same time, especially for early compressive strength.

Influences of Mineral Admixture on Properties of Porous Pervious Concrete Made of Recycled Aggregates

2014 ◽  
Vol 919-921 ◽  
pp. 1934-1938
Author(s):  
Ping Gong ◽  
Yu Zhou
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Permeability Coefficient ◽  
Mineral Admixture ◽  
Pervious Concrete ◽  
Recycled Aggregates

In this study,silica fume and fly ash were used to replace part of cement, the 28-days compressive strength and the permeability coefficient were tested to study influences of mineral admixture on properties of porous pervious concrete made of recycled aggregates.The results show the best effect is to multiplexed mix with fly ash and silica fume, the 28-day compressive strengths of concrete is higher than those single mixed or doesn’t mix any mineral admixture.

Study on Ultra-Strength Mortar Prepared with Mineral Admixture

2011 ◽  
Vol 675-677 ◽  
pp. 1073-1076
Author(s):  
Zu Quan Jin ◽  
Peng Zhang ◽  
Tie Jun Zhao ◽  
Bao Rong Hou
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Pore Structure ◽  
Silica Fume ◽  
Mineral Admixture ◽  
Replacement Rate ◽  
River Sand ◽  
Optimum Proportion ◽  
Curing Age

In this paper, preparation, property study of ultra-strength mortars with mineral admixture and clear river sand was carried out. The mineral admixture include fly ash, ultra-fine GGBS and silica fume. The experimental results show that the compressive strength of mortar improves with increasing amount of silica fume or ultra-fine GGBS. When the content of silica fume or ultra-fine GGBS is 30~35%, the compressive strength and flexural strength of mortar in curing age of 7 days are 100 MPa and 20MPa, respectively. But strength of mortar decreases with the increase replacement rate of fly ash. When the mortar mixes with combined of silica fume and ultra-fine GGBS, the optimum proportion of siliaca fume to ultra-fine GGBS is 2:3. And the compressive strength of mortar in curing age of 7 days is 75~100MPa when the mixed mineral admixture is 40~60%. The compressive strength of mortar is about 90MPa as it mix 60% of cement, 15% of silica fume, 15% of GGBS and 10% of fly ash. Moreover, the ultra strength mortar refines its pore structure and its capiliary pore (≥100nm) amount reduces by 78% compared to ordinary mortar.

Activity Evaluation of a Tailing in a Cementitious System

2017 ◽  
Vol 726 ◽  
pp. 515-520 ◽  
Author(s):  
Bing Hao Li ◽  
Lian Zhen Xiao ◽  
Ya Qing Fu
Keyword(s):  
Compressive Strength ◽  
Electrical Resistivity ◽  
Fly Ash ◽  
Activity Index ◽  
Resistivity Measurement ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Electrical Resistivity Measurement ◽  
Activity Evaluation ◽  
Two Peaks

Hydration activity of a tailing is evaluated by the hydration rate obtained from the electrical resistivity measurement and compressive strength in a cementitious hydration system as a mineral admixture. A plain paste and the pastes with tailing or fly ash by replacement of cement at water-binder ratio of 0.4 are prepared. The electrical resistivity of the paste samples was measured in 168h(7d) by a non-contact resistivity technique. Hydration activity of the tailing was also evaluated by measuring the compressive strength at the curing ages of 3d~90d to confirm the results from the electrical resistivity. It is found that the addition of a mineral admixture delays the occurrence of two peaks on the electrical resistivity differential curve and the delayed times are 3.32h and 6.10h for the sample with tailing, and 0.78h, 3.49h for the sample with fly ash. The rate values on the two peaks are decreased with incorporation of the tailing or fly ash. The activity evaluation results on the mineral admixtures from the resistivity measurement are consistent with the strength results before 7d. The resistivity as an activity index can provide a simple and fast way to evaluate mineral material activity at early ages. The effect of tailing and fly ash on compressive strength for a long term was also analyzed and the micro-structure of the pastes at 7d and 28d were observed by SEM.

Experiment and Research on the Influence of Mineral Admixture on Cement-Based Material Performance

2012 ◽  
Vol 174-177 ◽  
pp. 1446-1449 ◽  
Author(s):  
Xiao Hong Cong ◽  
Bin Xue ◽  
Jing Sun ◽  
Xiao Wei Sun
Keyword(s):  
Compressive Strength ◽  
Data Analysis ◽  
Fly Ash ◽  
Silica Fume ◽  
Cement Mortar ◽  
Mineral Admixture ◽  
Basic Material ◽  
Mixture Ratio

Cement mortar as the basic material and the fly ash and silicon fume as the research object, experiment and research were operated through adjusting the admixture replacing dosage and changing the mixture ratio of silica fume and fly ash. By testing the fluidity and strength and data analysis and discussion, some conclusions are drawn from the analysis, such as: fly ash makes the fluidity increasing with the admixture replacing dosage below 30%, and the fluidity declines with the mixture ratio of silica fume and fly ash increasing. 7d compressive strength decreases with the admixture replacing dosage increasing, 7d compressive strength increases slowly with the mix ratio of silica fume and fly ash. With the mix ratio of silica fume and fly ash increasing, 28d compressive strength of mortar also increases, and proper mix ratio of silica fume and fly ash is 1:1.

The Design and Application of Ballastless Track Enhanced Concrete Mineral Admixture

2014 ◽  
Vol 638-640 ◽  
pp. 1427-1430 ◽  
Author(s):  
Bao Guo Ma ◽  
Fang Jie Chen ◽  
Bing Liu Zhang ◽  
Chao Liang Lin
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mineral Admixture ◽  
Ballastless Track ◽  
Compressive Strength Of Concrete ◽  
Calcium Formate ◽  
Design And Application

Calcium formate and superfine powders comprised of fly ash, slag and silica fume have been used as raw marerials in this research. The results showed that when superfines powders were mixed with 1.5% calcium formate in a fixed porpotion, the 1 day and 28 day compressive strength of concrete can increase 133.7% and 115.9%, respectively.

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