scholarly journals Proportion Design Method and Water Stability of Cement-Emulsified Asphalt Cold Recycling Mixtures

2018 ◽  
Vol 238 ◽  
pp. 05009
Author(s):  
Junxiao Li ◽  
Wei Fu ◽  
Xiaobo Yin
Keyword(s):  
Cement Content ◽  
Design Method ◽  
Water Stability ◽  
Optimum Content ◽  
Cold Recycling ◽  
Emulsified Asphalt

Nowadays, a large amount of work has been done in the field of emulsified asphalt cold regeneration. Three different proportions of emulsified asphalt cold recycling mixtures were designed by mixing different ratios of new aggregates and RAP, the effect of cement content and RAP content on the mixtures's water stability was studied. The results show that the addition of cement can improve the mixtures's water stability, but there is an optimum content; the mixtures's water stability reduces with the increase of RAP content.

Research on the Mix Design of Cement Asphalt Concrete

2014 ◽  
Vol 887-888 ◽  
pp. 838-841
Author(s):  
Yun Hua Zhang ◽  
Jin Zhao ◽  
Jun Fu ◽  
Chun Mei Yu ◽  
Tao Xiang
Keyword(s):  
Asphalt Concrete ◽  
Cement Content ◽  
Mix Design ◽  
Optimum Content ◽  
Mix Proportion ◽  
Cleavage Strength ◽  
Added Water ◽  
Emulsified Asphalt

Effect of material mix proportion on strength of cement asphalt concrete (CAC) was studied based on 7d cleavage strength. Results indicate that the cleavage strength of CAC increase sharply with the increase of the cement content (0-6%), and the optimum content of added water and emulsified asphalt were 2% and 6% respectively while the cement content was 5%.

A Balanced Mix Design Method for Selecting the Optimum Binder Content of Cold In-Place Recycling Asphalt Mixtures

2019 ◽  
Vol 2673 (3) ◽  
pp. 526-539 ◽  
Author(s):  
Ahmed Saidi ◽  
Ayman Ali ◽  
Wade Lein ◽  
Yusuf Mehta
Keyword(s):  
Complex Modulus ◽  
Cement Content ◽  
Design Method ◽  
Binder Content ◽  
Asphalt Mixtures ◽  
Mix Design ◽  
Air Voids ◽  
Foamed Asphalt ◽  
Indirect Tensile ◽  
Emulsified Asphalt

The objective of this paper is to present a procedure for designing cold in-place recycling (CIR) mixtures through balancing rutting and cracking for these mixtures. Four CIR mixtures were prepared using two recycling agents (foamed and emulsified asphalts), and compacted at two gyration levels (30 and 70 gyrations). The CIR mixtures were prepared at a constant water content of 3% and a constant cement content of 1% while curing of the compacted samples was conducted by placing them in an oven for three days at 140°F (dry curing). The CoreLok device was used for measuring air voids in compacted samples. The rutting susceptibility of these mixtures was then evaluated using the asphalt pavement analyzer (APA) and dynamic complex modulus (|E*|) while resistance to cracking was assessed using the indirect tensile strength (ITS) test and fracture energy as determined using the semi-circular bend (SCB-FE) test. A demonstration of how these tests were utilized to select a performance balanced optimum binder content for each of the four CIR mixes was also presented. The developed balanced mix design approach was used successfully for designing four CIR mixtures and selecting the optimum binder content for each mix. The results also showed that using a higher compaction level leads to increasing both foamed and emulsified asphalt CIR mixtures’ ability to resist rutting. In terms of cracking, SCB-FE results showed that foamed asphalt mixtures were better at resisting cracking than emulsified asphalt CIR mixtures.

scholarly journals Composition Design and Performance Evaluation of Emulsified Asphalt Cold Recycled Mixtures

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2682
Author(s):  
Yuhui Pi ◽  
Zhe Huang ◽  
Yingxing Pi ◽  
Guangcan Li ◽  
Yan Li
Keyword(s):  
High Temperature ◽  
Stress Level ◽  
Performance Test ◽  
Cement Content ◽  
Asphalt Binder ◽  
Temperature Stability ◽  
Base Layer ◽  
Water Stability ◽  
High Temperature Stability ◽  
Emulsified Asphalt

Based on an analysis of the cold regeneration mechanism of emulsified asphalt, the emulsified asphalt binders and cement were applied to prepare the cold recycled mixtures, and the main technical performances of the designed mixtures were evaluated, including high-temperature stability, water stability, and fatigue characteristics. A high content of 65% recycled asphalt pavement (RAP) material was used with some new aggregates and mineral powders, and the optimal emulsified asphalt binder and cement dosages were determined as 2.9% and 1.5% respectively. The technical performance test results show that: (1) The well-designed emulsified asphalt cold recycled mixtures have good high-temperature stability and water stability, and can meet the requirements of the road base layer and the lower layer. (2) When the stress level is lower, the fatigue performance of mixtures with lower emulsified asphalt binder dosage and lower cement content is better, but when the stress level is higher, the high dosage of emulsified asphalt binder is more favorable, while the cement content has little effect on the fatigue property. (3) The emulsified asphalt cold recycled mixtures have relatively poor fatigue resistance, and their fatigue life is significantly lower than that of the hot mixed asphalt mixtures.

Experimental Study on Water Stability of Cold Recycled Mixture Stabilized with Emulsified Asphalt

2012 ◽  
Vol 204-208 ◽  
pp. 1914-1917
Author(s):  
Ming Hui Liu
Keyword(s):  
Asphalt Pavement ◽  
Water Stability ◽  
Experiment Research ◽  
Asphalt Cement ◽  
Freeze Thaw ◽  
Recycling Technology ◽  
Split Test ◽  
Cold Recycling ◽  
Marshall Stability ◽  
Emulsified Asphalt

Abstract: Water damage on asphalt pavement will accelerate pavement destruction, and decrease the service life of highway. Water stability of recycled mixture especially should be strengthened in design and construction of cold-recycled pavement. Taking for cold recycling technology as research object , We studied water stability and freeze-thaw stability of cold recycled mixture stabilized with emulsified asphalt, cement and emulsified asphalt through tests of Marshall stability and immersion Marshall、split test 、soaking split test and freeze-thaw split etc. The results obtained show that: Water stability of Cold recycled mixture stabilized two different additives all can satisfy requirement, and cold recycled mixture adding little cement has better stability. Cold recycled mixture stabilized emulsified asphalt can be used as highway base or sub-surface of pavement. The experiment research results provide a reliable reference for cold recycled mixture design and its applicability.

scholarly journals Study on the Parameter Optimization and Strength Mechanism of Coal Gangue Emulsified Asphalt Mixture

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
ZhanLiang Liu ◽  
Chen Zhang ◽  
Xin Qu
Keyword(s):  
Power Plants ◽  
Coupling Effect ◽  
Asphalt Mixture ◽  
Microscopic Analysis ◽  
Coal Gangue ◽  
Orthogonal Experimental Design ◽  
Water Stability ◽  
Use Of Resources ◽  
Emulsified Asphalt

Emulsified asphalt mixture has the characteristics of convenient construction and durable performance, but its poor early strength and demulsification seriously restrict the popularization and application of this material. At present, the coal gangue produced by coal-fired power plants is generally discarded, resulting in serious environmental pollution. The combination of coal gangue and emulsified asphalt can explore an efficient utilization way for more and more coal gangue and also solve the curing problem of asphalt. In order to give full play to the advantages of existing materials and make rational use of resources, this paper studies the factors affecting the performance of coal gangue emulsified asphalt mixture based on orthogonal experimental design and optimizes its material composition parameters by considering the coupling effect of two factors. The water stability of coal gangue emulsified asphalt mixture is evaluated by the immersion Marshall test. Finally, the strength formation mechanism of coal gangue emulsified asphalt mixture is analyzed from the microscopic point of view. The results determined 7.5% as the optimum amount of emulsified asphalt in coal gangue emulsified asphalt mixture and recommended the best parameter combination of 7.5% emulsified asphalt, 6% coal gangue, and 5% water consumption. With the increase of coal gangue content, the water loss resistance of emulsified asphalt mixture increases gradually, and the water stability of emulsified asphalt mixture can be improved by adding coal gangue. According to the microscopic analysis, the strength of the mixture is formed by the joint action of emulsified asphalt and coal gangue, in which the hydration products of coal gangue and asphalt play the role of cementation and strength together. The ordinary emulsified asphalt mortar mainly contains CaCO3, which mainly plays the role of physical filling.

Design Method and Study on Water Stability of Warm Mixing Regeneration Mixture Based on Interface Effect

2015 ◽  
Vol 713-715 ◽  
pp. 2640-2643
Author(s):  
Hui Qiang Chen
Keyword(s):  
Design Method ◽  
Design Procedure ◽  
Interface Effect ◽  
Water Stability ◽  
Negative Effects ◽  
Form Change ◽  
Splitting Strength ◽  
Before And After

The paper introduced the design procedure and design method of warm mixing regeneration mixture AC13. The water stability of warm mixing regeneration mixture was studied systematically with Evotherm warm mixing agent and self-prepared interface dispersant, the form change of old asphalt membrane and old aggregate in RAP was analyzed based on interface effect, and the optimum interface dispersant dosage was determined on this base. Results showed that: with the the interface dispersant dosage rising, significant changes of the TSR and splitting strength frozen-thawed before and after of warm mixing regeneration mixture occurred; when the interface dispersant dosage reached 2‰(based on RAP), both the TSR and splitting strength frozen-thawed before and after of warm mixing regeneration mixture were high,which verified the excellent water stability of warm mixing regeneration mixture; superfluous interface dispersant had negative effects on the water stability of warm mixing regeneration mixture.The exfoliation between old asphalt membrane and old aggregate and secondary coat were realized by interface effect.

Performance of Emulsified Asphalt Full Thickness Cold Recycling Subgrade Materials

2014 ◽  
Vol 915-916 ◽  
pp. 704-708 ◽  
Author(s):  
Jun Xiao Li ◽  
Xiao Bo Yin ◽  
Jian Yuan ◽  
He Chao Zang ◽  
Zong Rui Hao
Keyword(s):  
Network Structure ◽  
Unconfined Compressive Strength ◽  
Cement Hydration ◽  
Full Thickness ◽  
Hydration Products ◽  
Space Network ◽  
Tightly Coupled ◽  
Indirect Tensile ◽  
Cold Recycling ◽  
Emulsified Asphalt

Full thickness cold recycling subgrade materials were prepared by cement-emulsified asphalt solidified RAP and stabilized soil.The effect of adding amount of emulsified asphalts change on unconfined compressive strength, indirect tensile strength and water stability of cold recycled mixtures with different ratios was studied,and the mechanism of action of cement and emulsified asphalt in the mixtures was analysised via microscopic test. The results show that a proper addition of emulsified asphalt can improve the performance of cold recycled mixtures and the best emulsified asphalt mixing content is 3%. Microscopic test indicate that the cement hydration products space network structure interfinger with the emulsified asphalt network structure, so the cold recycled mixture tightly coupled to a semi-rigid whole, and the mixtures strength can form and develop.

scholarly journals Consumption of superplasticizer admixture for different cements and their binder efficiency

2019 ◽  
Vol 12 (6) ◽  
pp. 1260-1287
Author(s):  
R. T. CECEL ◽  
P. C. R. A. ABRÃO ◽  
F. A. CARDOSO ◽  
V. M. JOHN
Keyword(s):  
Water Content ◽  
Environmental Impacts ◽  
Cement Content ◽  
The Other ◽  
Carbon Intensity ◽  
Limestone Filler ◽  
Blended Cements ◽  
Significant Variability ◽  
Optimum Content ◽  
Flow Table

Abstract The optimum content of ether polycarboxylate-based superplasticizer, determined by rotational rheometry, and its effects on the environmental impacts of concretes were studied for cement and limestone filler. To assess the consistency and water reduction, flow-table tests were performed. Then, cement content reduction and binder and carbon intensity indexes were determined through estimation based on theoretical concretes. The evaluated pure and blended cements present significant variability of the optimum consumption of the admixture. The fillers consumed less superplasticizer per area than the other materials and compositions with fillers allowed for greater reduction of water content. The mixtures with superplasticizer presented lower cement rate and binder and carbon intensity indexes. The usage of this type of admixture in optimal content can reduce environment impacts, according to the parameters analyzed.

scholarly journals Performance Evaluation of Recycled Asphalt Pavement Materials and Cold Recycling Mixtures Designed with Vibratory Compaction Method

2019 ◽  
Vol 9 (15) ◽  
pp. 3167
Author(s):  
Yuhui Pi ◽  
Zhe Li ◽  
Yingxing Pi ◽  
Zhe Huang ◽  
Guangcan Li
Keyword(s):  
Performance Evaluation ◽  
Asphalt Pavement ◽  
Heavy Duty ◽  
Recycled Asphalt Pavement ◽  
Recycled Asphalt ◽  
Accelerated Curing ◽  
Vibratory Compaction ◽  
Cold Recycling ◽  
Emulsified Asphalt ◽  
Compaction Method

In this paper, the basic composition and performance evaluation of the recycled asphalt pavement (RAP) materials were firstly analyzed, and two methods were proposed to evaluate strength characteristics of RAP materials, including a triaxial method for the residual strength and the mortar cementing method for the strength of RAP lump. Then, the cold recycling technology was applied on RAP materials with emulsified asphalt by using vibratory compaction and heavy-duty compaction methods (Proctor compaction method), and the results showed that the maximum dry density obtained by heavy-duty compaction was closer to the actual situation. Finally, the effects of wetting water, emulsified asphalt dosage and curing conditions on the performance of the specimens were investigated. It was found that when the emulsified asphalt was mixed uniformly, whether or not to add the wetting water have almost no effect on the strength of the molded specimens. When the matrix asphalt content of the emulsified asphalt was 30%~60%, the water could be directly added to the cold recycling mixture. The intensity of accelerated curing for two days at 40 °C was approximately equal to that of natural curing for three days, while that of accelerated curing for three days at 40 °C was approximately equal to that of natural curing for seven days, which provided a basis for the short-term laboratory test.

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