scholarly journals Performance Evaluation of Semiplastic Recycled Cold Asphalt Using Noncement Binders

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Byung Jae Lee ◽  
Jin Wook Bang ◽  
Jeong Su Kim ◽  
Young Il Jang

The optimal mixing conditions for semiplastic recycled cold asphalt, which recycled waste asphalt and used noncement binders (NCB), were assessed through verification of the performance. The NCB of 6% desulfurization gypsum mixing was found to have the most outstanding properties. For the Marshall stability, 4% (NCB) filler mixing brought about a 1.92-time strength increase effect compared to OPC (2%) and was improved when using modified asphalt and SBR. The flow test results showed that although an increase dosage of filler and SBR decreased the flow value of the semiplastic recycled cold asphalt, an increase dosage of asphalt emulsion improved the flow value. The indirect tensile strength and liquid immersion residual stability for the condition with greatest Marshall stability were most outstanding with 0.95 MPa and 83.6%, respectively. Evaluation of the recycled cold asphalt abrasion durability revealed that for the case of mixing more than 4% NCB the mass loss rate was lower than 20%. The abrasion durability was found to improve when using modified emulsified asphalt and SBR substitution. From the test results, it was found that the optimal mixing proportion of semiplastic recycled cold asphalt satisfied mechanical properties and durability is NCB with 4%, emulsified asphalt with 3%, and SBR substitution with 20%.

2015 ◽  
Vol 665 ◽  
pp. 185-188
Author(s):  
Byung Jae Lee ◽  
Jeong Su Kim ◽  
Yong Il Jang

In this study, the optimal mixing conditions for recycled cold asphalt, which recycled waste asphalt and used cementless binders, was assessed through verification of the performance. The cementless binder mixing ratio of 6% desulfurization gypsum substitution rate for blast furnace slag was found to have the most outstanding properties. For the Marshall stability, 4% filler mixing brought about a 1.92 times strength increase effect compared to OPC. The flow value testing showed that an increase in the use of asphalt emulsion resulted in an increased flow value while it decreased with the increase in filler substitution rate. The optimal mixing condition that satisfied mechanical performance and durability among the test conditions assessed in this study was found to be 4% filler mixed.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Jin Wook Bang ◽  
Byung Jae Lee ◽  
Yun Yong Kim

Mechanical tests were carried out to evaluate the influence and effects of fluidity and compressive strength of cement grout on semirigid asphalt pavement. An open graded asphalt skeleton was designed in order to achieve target porosity in the range of 18~22%. In addition, four types of cement grout mixtures were produced with varying mix proportions with ultrarapid hardening cement and chemical admixtures, that is, accelerating and retarding agents. For the semirigid pavement specimens, mechanical experiments to measure properties such as porosity, flexural strength, Marshall stability, and wheel tracking resistance were carried out. The test results demonstrated that the flow time (fluidity) of cement grout is the most significant factor that determines the mechanical properties of semirigid asphalt specimens under constant condition of the open graded asphalt skeleton. For the semirigid pavement mixing proportion in the current study, it is recommended that the porosity of the open graded asphalt skeleton and flow time of cement grout should be 20% and within 12 seconds, respectively.


Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 670
Author(s):  
Preeda Chaturabong

Chip seal bleeding is influenced by many factors, including design inputs, material properties, and project-specific conditions. It reduces the surface texture of the pavement and thus compromises the safety of the traveling public. Even though factors that bring about premature bleeding are known, currently, no laboratory test methods for evaluating bleeding in chip seals have been specified. The objective of this paper is to present the results of an investigation of the influence factors of asphalt emulsion residue properties measured by the ASTM D7405 multiple stress creep and recovery (MSCR) test, as well as other factors related to chip seal bleeding resistance as measured by the modified loaded wheel test (MLWT). In this study, the MSCR test was used as a tool for evaluating the performance of asphalt emulsions because it has been identified as a potential test related to bleeding in the field. In addition, MLWT was selected as a tool for evaluating chip seal bleeding performance in the laboratory. The results of the MLWT showed that the emulsion application rate (EAR), aggregate gradation, and emulsion properties were significant factors affecting bleeding. The MSCR test was found to be a promising tool for the performance evaluation of asphalt emulsion residue, as the test was able to differentiate between emulsion chemistries and modifications in terms of sensitivity to both temperature and stress. In relation to chip seal bleeding resistance, only the creep compliance (Jnr) obtained from the MSCR test results was identified as a significant property affecting potential for bleeding.


2011 ◽  
Vol 71-78 ◽  
pp. 928-931
Author(s):  
Jin Liang Wu ◽  
Yong Xing Zhang ◽  
Chun Sun Zhang

Nowadays, there are dominantly two ways of producing modified emulsified asphalt ,one of which is to emulsify modified asphalt, the other to modify asphalt emulsion. But they have the same defect that modifier cannot be evenly mixed with asphalt emulsion, which has side effect on the performance of modified emulsified asphalt. The emulsified asphalt and modifier have different traits in structure and property. In order to make the modifier disperse in asphalt emulsion evenly to improve the performance of modified emulsified asphalt, a tentative idea is brought forward: we shall utilize in-situ polymerization and core-shell structure to enhance feature of emulsified asphalt. Core-shell structure is a method of synthesizing composite material, which can assist to achieve sound effect of the two kinds of materials. The point to emphasize is, in this paper, the introduction and feasibility of the method, its specialty against current mainly methods, the difficulties encountered in practice as well as its promising prospect and the anticipated target to achieve will all be illustrated.


2020 ◽  
Vol 2 (1) ◽  
pp. 28-35
Author(s):  
Rokki Manurung ◽  
Sutan Simanjuntak ◽  
Jesayas Sembiring ◽  
Richard A.M. Napitupulu ◽  
Suriady Sihombing

Composites are materials which are mixed with one or more different and heterogeneous reinforcement. Matrix materials can generally be polymers, ceramics and metals. The matrix in the composite serves to distribute the load into all reinforcing material. Matrix properties are usually ductile. The reinforcing material in the composite has the role of holding the load received by the composite material. The nature of the reinforcing material is usually rigid and tough. Strengthening materials commonly used so far are carbon fiber, glass fiber, ceramics. The use of natural fibers as a type of fiber that has advantages began to be applied as a reinforcing material in polymer composites. This study seeks to see the effect of the use of bamboo natural fibers in polyester resin matrix on the strength of polymer composites with random and straight lengthwise fiber variations. From the tensile test results it can be seen that bamboo fibers can increase the strength of polymer composites made from polyester resin and the position of the longitudinal fibers gives a significantly more strength increase than random fibers.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1850
Author(s):  
Jinjun Guo ◽  
Ting Guo ◽  
Shiwei Zhang ◽  
Yan Lu

The freezing and thawing of construction concrete is becoming an increasingly important structural challenge. In this study, a shrinkage-compensating concrete based on a double expansive admixture was developed and its frost resistance was assessed through rapid freezing and thawing cycling. The frost resistance of the concrete was derived through the measurement and calculation of the relative dynamic modulus of elasticity (RDME) and the mass loss rate (MLR), and the freezing- and thawing-cycle microstructures and products of concretes with different expansive agents were analyzed using scanning electron microscopy (SEM). It was shown that changes in the properties of the concrete under freezing and thawing could be divided into three stages: slow-damage stage, fast-damage stage, and stable stage. Compared to concrete without an expansive agent, a single-expansive-agent concrete demonstrated excellent frost resistance during the slow-damage stage, but the frost resistance rapidly decreased during the fast-damage age. After 150 cycles (the stable-damage stage), the concrete with a U-type expansive agent (UEA): MgO expansive agent (MEA) mix proportion of 2:1 had the best frost resistance, with RDME and MLR values 17.35% higher and 25.1% lower respectively, than that of an expansive-agent-free concrete. These test results provide a basis for the study of frost resistance in large-scale hydraulic concrete structures.


2019 ◽  
Vol 9 (5) ◽  
pp. 972 ◽  
Author(s):  
Young-Il Jang ◽  
Byung-Jae Lee ◽  
Jong-Won Lee

The goal of this study was to improve the water purification performance of secondary concrete products that can be used in rivers and streams. To this end, mortar and porous concrete were produced by adding both de-nitrifying phosphate accumulating organisms ((D)PAOs) and zeolite, and their mechanical properties and water purification performance were analyzed. The compression strength test results showed that the strength was the highest when the mixing ratios of (D)PAOs and zeolite were set to 10% and 5%, respectively. For better contaminant adsorption, however, the optimal mixing ratio of zeolite was determined to be 10%. When the mixing ratio of (D)PAOs was set to 10%, the concentrations of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) decreased by 57.9% and 89.9%, respectively, after seven days of immersion when compared to the initial concentrations. When compared to plain porous concrete, the total nitrogen (T-N) and total phosphorus (T-P) removal ratios of the develop concrete were 11.0% and 17.8% higher, respectively. When the mixing ratios of (D)PAOs and zeolite were set to 10% for both, the T-N and T-P removal ratios were determined to be 86.3% and 88.1%, respectively, while the BOD and COD concentrations were 2.668 mg/L and 16.915 mg/L, respectively. In simpler terms, the water purification performance was up to 17% higher in the concrete mixed with both 10% (D)PAOs and 10% zeolite than in the concrete mixed with 10% (D)PAOs only. Overall, the optimal mixing ratios of (D)PAOs and zeolite to maximize the water purification effect of secondary concrete products while maintaining their strengths equivalent to or higher than those of their corresponding plain concrete products are considered to be 10% for both.


2014 ◽  
Vol 587-589 ◽  
pp. 1132-1136
Author(s):  
Yue Li ◽  
Ping Wang

Uniaxial compression and bending test of CA mortar, which have six different dosage of emulsified asphalt and the same dry material, is carried out with a electronic universal test machine. It turns out that: when the dosage of emulsified asphalt is lacked, the CA mortar cannot be uniform and stable slurry system; within the range of 300~680 mL emulsified asphalt, slurry state of mortar is good, no separation, and have good liquidity, in this range, with the increasing dosage of emulsified asphalt, compressive strength, elastic modulus and peak strain are gradually reduced, while ratio of bending strength to compressive strength rise at the beginning, then decline within a narrow range; The 1st and 2nd slurry is not stable, they appear separation and the surfaced asphalt, which have similar appearance and mechanical properties to cement mortar, and the last four groups of test results have great difference from the former two groups.


2013 ◽  
Vol 423-426 ◽  
pp. 1334-1338 ◽  
Author(s):  
Jian Zhang ◽  
Shao Fei Yuan ◽  
Kui Hong Wang ◽  
Qin Li

The paper preheated poplar and Chinese fir with microwave before dipping into fire retardant solution with the purpose of improving their permeability. The test results showed that microwave increased the routs for liquid which proved to be a feasible way to facilitate fire retardant solution to enter into wood. Fire retardant loading dosage (FRLD) and implantation depth (ID) increased for both poplar and Chinese fir. Fire retardant properties such as oxygen index (OI), mass loss rate (MLR) and flame combustion time (FCT) increased and can meet the fire retardant wood requirements defined by standard of GA/T 42.1-92.


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