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Characteristics of aggregate gradation, drain down and stabilizing agents in stone matrix asphalt mixtures: A state of art review

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第2期9卷 167-179页

作者： Lekhaz Devulapalli Goutham Sarang Saravanan Kothandaraman The Bombay Textile Research Association Mumbai 400086India School of Civil Engineering Vellore Institute of TechnologyChennai 600127India

Over the years stone matrix asphalt(SMA)mixtures have evolved significantly and research works have presented some promising *** made the paving industries to increase the usage of SMA mixtures in the pavement ***,SMA mixtures have certain challenges or setbacks,which require comprehensive *** aim of the review paper is to present some of the challenges in SMA mixtures and their mitigations *** is observed that several challenges(i.e.,aggregate gradation,stone-onstone contact,drain down and stabilizing agents)related to SMA mixtures are addressed by the *** agencies have suggested their own aggregate gradation based on their experience,location,climatic conditions and available manufacturing facilities,and they are working ***-on-stone contact is achieved with proper aggregate gradation and failure to meet the same will reduce the *** down is major concern in the SMA mixtures since it controls overall mixture ***,researchers shown out the most importance to curtail the *** researchers followed ASTM D6390 and National Cooperative Highway Research Program(NCHRP No.424)procedure to evaluate the drain down and concluded that drain down should be less than0.3%(by weight of mixture).Apart from that,researchers are trying different stabilizing agents to reduce the drain ***,stabilizing agents such as fibers and polymers have a positive ***,suitable waste and recycle products are used as stabilizing agent to reduce drain down and environmental *** of which coconut fiber has shown some promising results,however,comprehensive research is required in this *** the other hand,0.3%of cellulose fiber is working as a good stabilizing agent and can be used without conducting drain down *** review paper provides a complete knowledge about different stabilizing agents used in SMA mixtures to minimize the drain down.

关键词： Stone matrix asphalt Drain down Stabilizing agents Stone-on-stone contact aggregate gradation Nominal maximum aggregate size

A Modeling Method for Predicting the Strength of Cemented Paste Backfill Based on a Combination of aggregate gradation Optimization and LSTM

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Journal of Renewable Materials 2022年第12期10卷 3539-3558页

作者： Bo Zhang Keqing Li Siqi Zhang Yafei Hu Bin Han School of Civil and Re source Engineering University of Science and Technology Beijing Beijing100083China Key Laboratory of Ministry of Educ ation of China for Eficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China

Cemented paste backill(CPB)is a susta inable mining technology that is widely used in mines and helps to improve the mine *** investigate the relationship between aggregate grading and different affecting factors and the uniaxial compressive strength(UCS)of the cemented paste backill(CPB),Talbol gradation theory and neural networks is used to evaluate aggregate gradation to determine the optimum aggregate *** mixed aggregate ratio with the least amount of cement(waste stone content river sand content=7:3)is obtained by using Talbol grading theory and pile compactness function and combined with *** addition,the response surface method is used to design strength speaific ratio *** UCS prediction model which ues the ISTM and considers the aggregates gradation have high *** root mean square error(RMSE)of the prediction results is 0.0914,the coefficient of determination(R^(2))is 0.9973 and the variance account for(VAF)is *** with back propagation neural network(BP-ANN),extreme lea ming machine(ELM)and madal basis function neural network(RBF ANN),LSTM can efectively characterize the nonlinear relationship between UCS and individual affecting factors and predict UCS with high *** sensitivity analysis of different affecting factors on UCS shows that all 4 factors have significant effect on UCS and sensitivity is in the following ranking:cement content(0.9264)>slurry concentration(0.9179)>aggregate gradation(waste rodk content)(0.9031)>curing time(09031).

关键词： Backill aggregate gradation machine learning uniaxial compressive strength cemented paste backill

The aggregate gradation for the Porous Concrete Pervious Road Base Material

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Journal of Wuhan University of Technology(Materials Science) 2008年第3期23卷 391-394页

作者：杨志峰沈卫国 School of Material Science and Engineering Wuhan University of Technology Research Institute of Highway Ministry of CommunicationBeijing 100088China

The effects of the proportion of fine aggregate, the maximum size of the aggregate and the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate on the properties of the porous concrete are investigated. Results indicate that the porous concrete with a cement dosage only 150 kg/m^3 has high strength and satisfying permeability when the aggregate has a passing percentage of 4.75 mm around 10% to 15%, with the increase of the maximum size of the aggregate, the strength of the porous concrete decreases and the permeability increases. When the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate is about 20%, there are no interference among the particles by Weymouth theory, the strength of the pervious porous concrete reaches the peak value. The optimum continues gradation limit of the aggregate for porous concrete pervious road base material is recommended according to the theoretical calculation and experimental results.

关键词： aggregate gradation porous concrete pervious road base maximum size strength permeability

Effect of aggregate gradation on low temperature performance of asphalt paving mixtures

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Journal of Harbin Institute of Technology(New Series) 2011年第1期18卷 11-17页

作者：谭忆秋徐慧宁石昆磊吴建涛 School of Traffic Science and Engineering Harbin Institute of Technology Shanghai Municipal Engineering Design General Institute

Low temperature cracking has become one of the important factors that diminish asphalt pavement's ride quality and service *** in cold region,cracking caused by low temperature is the main distress *** paper discussed the effect of aggregate gradation on the low temperature performance in asphalt paving mixtures.A total of 11 asphalt mixtures with 11 different aggregate gradations and one asphalt binder content were *** properties of the coarse aggregate and asphalt mixtures showed aggregate grading has a significant impact on the degree of aggregate interlock in asphalt mixtures.A trend is existed in the low temperature performance with the change of *** the aid of mathematic statistics,it indicates gradation affects the low temperature performance *** findings also indicate the relationship between the degree of aggregate interlock in asphalt mixtures and the low temperature performance:With the stone-to-stone contact developed,the mixture has a high energy to resist contract and deformation at low *** properties of fine aggregate and asphalt play an important part in resisting low temperature cracking in floating *** it provides lower energy to resist low temperature cracking compared to the skeleton structure.

关键词： asphalt mixtures aggregate gradation low temperature performance the degree of aggregate interlock rank sum test

Laboratory performance of stone matrix asphalt mixtures with two aggregate gradations

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Journal of Modern Transportation 2015年第2期23卷 130-136页

作者： Goutham Sarang B.M.Lekha J.S.Geethu A.U.Ravi Shankar Department of Civil Engineering National Institute of Technology Karnataka

Stone matrix asphalt （SMA） is a gap-graded bituminous mixture which can be used in surface layer of high volume pavements. The mixture has higher concen- trations of coarse aggregates, providing strength and rut resistance to the mixture, and higher asphalt content giving durability. There must be a proper stone-to-stone contact between the coarse aggregates of SMA, and hence aggre- gate gradation is an important factor in this mixture. In the current study, two aggregate gradations, with nominal maximum aggregate sizes （NMAS） 16 and 13 mm were adopted to prepare SMA mixtures and their laboratory performances were compared. Polymer-modified bitumen （PMB） was used as the binder material and no stabilising additive was used, since drain down was within permissible limits for both mixtures with PMB. Conventional cylin- drical specimens were prepared in superpave gyratory compactor with bitumen contents 5.0 %, 5.5 %, 6.0 %, 6.5 % and 7.0 % by weight of aggregates, and volumetric and Marshall properties were determined. Tensile strength, behaviour to repeated loading etc. were checked for cylindrical specimens prepared at optimum bitumen con- tent, whereas specially prepared slab specimens were used to check the rutting resistance of SMA mixtures. From the laboratory study, it was observed that, out of the two SMA mixtures, the one with NMAS 16 mm performed better compared to the other. These improved properties may be attributed towards the larger coarse aggregate sizes in the mixture.

关键词： Stone matrix asphalt Stone-to-stone contactDrain down aggregate gradation Nominal maximumaggregate size

Experimental Characterization of Rutting Performance of HMA Designed with aggregate gradations According to Superpave and Marshall Methods

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World Journal of Engineering and Technology 2016年第3期4卷 477-487页

作者： Basim H. Al-Humeidawi Roads and Transport Engineering Department College of Engineering University of Al-Qadisiyah Al-Diwaniya Iraq

The permanent deformation (rutting) of pavement is a major distress in flexible pavement. It is related to vehicles properties and/or pavement materials and conditions. This article presents an extensive experimental investigation in order to compare between the aggregate gradation according to Superpave and Marshall methods of asphalt concrete mix design on pavement rutting and to examine the sensitivity of rutting resistance to aggregate gradation. A wheel truck machine has been used for measurement of pavement rutting (permanent deformation). The tests were carried out at two controlled different air temperature 55℃ and 25℃. The results obtained showed that the adopting of aggregate gradation procedure of Superpave method of pavement mix design for Marshall method of asphalt concrete mix design can reduce the pavement rutting by about 50%. This achievement may be related to missing of three sieves in aggregate gradation procedure of Marshall method which controls rounded and finer aggregate particles. These sieves provide more continuity for aggregate gradation to ensure filling unnecessary gaps and produce more contact points between the aggregates in Hot Mix Asphalt (HMA). The outputs of the research support modifying Marshall method of asphalt concrete mix design by adopting aggregate gradation proposed in Superpave method. The results of study also showed that the coarser aggregate provided more resistance to pavement rutting.

关键词： Superpave Marshall Method Pavement Rutting aggregate gradation Experimental Investigation

Splitting Strength Analyses of Cement Asphalt Emulsion Mixtures with Different aggregate gradations Using Discrete Element Method

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Splitting Strength Analyses of Cement Asphalt Emulsion Mixtu...

Design Method and Performance for Large Stone Porous Asphalt Mixtures

2012年海峡两岸破坏科学/材料试验学术会议

作者： Zhenjun Wang Rui Wang Jingjing Xiao Wei Jiang Yongfeng Wei School of Materials Science & Engineering Chang'an University Engineering Research Central of Pavement Materials Ministry of Education of P.R.ChinaChang'an University School of Highway Chang'an University

The splitting strength of cement asphalt emulsion mixtures with different aggregate gradation types were investigated in this paper,which was simulated with the Discrete Element Method(DEM) by bond parameters in two *** linear contact model and the Burger’s model were *** splitting strength was analyzed by combining with stress-strain response under compressive loads on the *** results indicate that the mixtures with the aggregate gradation of suspended dense structure have the highest load *** kind of aggregate gradation type is suitable to splitting strength improvement of the *** DEM can be used to analyze the splitting strength of the mixtures consistently with laboratory observations.

关键词： cement asphalt emulsion mixtures discrete element method(DEM) splitting strength aggregate gradation

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Journal of Wuhan University of Technology(Materials Science) 2010年第5期25卷 871-876页

作者：赵永利黄晓明 School of Transportation Southeast University

Design method for large stone porous asphalt mixtures （LSPM） was analyzed to avoid the early distresses of semi-rigid asphalt pavements. Based on stone-to-stone skeleton structure concept, processes of LSPM gradation design was given. The gradation composite design for LSPM shows that the LSPM nominal maximum size （ N MS） should be larger than 26.5 mm, and the NMS sieve passing percentage should be greater than 50%. Through experiments and calculations on the volume properties of the aggregate, the range of aggregate gradation curve of LSPM was given. In terms of asphalt binder＇s normalized test results, MAC-70 and SBS modified asphalt were selected as the asphalt binders. The applicability of large scale Marshall Method and gyratory compaction method to shape specimens was investigated. Based on the asphalt mixture performance evaluation, the optimum asphalt content range （3.1%-3.6%）, the bitumen film＇s thickness range （13-16 μm） and the air void range （13%-18 %） were recommended. Finally, LSPM was tested by the laboratory performance tests including rutting resistance test, fatigue test and water stability test. The theoretic and practical analysis shows that LSPM has a good performance on water permeability, rutting resistance and reflection crack resistance.

关键词： large stone porous asphalt mixtures (LSPM) mixture design performance aggregate gradation optimum asphalt content

“Noisy”issues in road acoustics:A white paper

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Journal of Road Engineering 2022年第1期2卷 61-69页

作者： Filippo Giammaria Praticò DIIES Department University Mediterranea of Reggio CalabriaReggio Calabria 89124Italy

Despite almost a century of studies dealing with traffic noise,researchers and practitioners still face old and new issues when designing a low-noise *** that,this manuscript aims at focusing on a number of unsolved questions,namely theoretical or technological.1)Is it viable to balance diverse road-related needs(i.e.,noise,expected life,texture levels,and friction)?2)How much does the pavement material affect its acoustic performance(the remaining factors being constant)?3)How much reliable is the relationship between road texture and mixture aggregate gradation?Based on the analysis of these issues,it emerges that:1)optimal pavement design involves complex mix optimization and there are theoretical and practical bases to set up a balanced approach to address the complexity of pavement design;2)high percentages of crumb rubber could optimise road acoustic response but this latter has a relationship with the tyre/road noise(expressed,for example,in terms of close proximity index)that calls for further investigation;3)aggregate gradation appears to be a reliable basis to predict surface texture and therefore,under given boundary conditions,tyre/road noise;and 4)further studies and investigations are needed in terms of local calibration of deterioration curves and setting up of a sound method to assess the frequency response of asphalt concretes and to govern on-site noise indicators based on mixture properties.

关键词： aggregate gradation Complex design Noise Surface texture Tyre/road interaction