Review on frost resistance and anti-clogging of pervious concrete

Pervious concrete is a special type of concrete that is of high porosity and contains no or a small amount of fine aggregate,and it is an important basic material for sponge city construction.The presence of a large number of connected pores inside pervious concrete leads to a marked difference in durability failure mechanism compared with that of ordinary concrete.In this study,the frost resistance and anti-clogging of pervious concrete were introduced in detail,and the methods to improve their performance were summarized systematically.The cracking pattern of pervious concrete is influenced by geometric characteristics and three-dimensional morphological features of pores,resulting in its crack generation,development,and geometry being significantly different from those of ordinary concrete,thus leading to different freeze-thaw cycle mechanisms.In addition,due to its different pore structure compared to ordinary concrete,three types of clogging mechanisms,affecting the long-term permeability of pervious concrete were elaborated systematically(i.e.,physical clogging,biological clogging,and chemical clogging).And the ways to improve the anti-clogging of pervious concrete are systematically presented from multiple perspectives.Finally,in order to broaden the engineering applications of pervious concrete,some research proposals are presented in this study.

New innovations in pavement materials and engineering:A review on pavement engineering research 2021

Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges.In the past 10 years,the pavement infrastructure strongly supports the rapid development of the global social economy.New theories,new methods,new technologies and new materials related to pavement engineering are emerging.Deterioration of pavement infrastructure is a typical multi-physics problem.Because of actual coupled behaviors of traffic and environmental conditions,predictions of pavement service life become more and more complicated and require a deep knowledge of pavement material analysis.In order to summarize the current and determine the future research of pavement engineering,Journal of Traffic and Transportation Engineering(English Edition)has launched a review paper on the topic of"New innovations in pavement materials and engineering:A review on pavement engineering research 2021".Based on the joint-effort of 43 scholars from 24 well-known universities in highway engineering,this review paper systematically analyzes the research status and future development direction of 5 major fields of pavement engineering in the world.The content includes asphalt binder performance and modeling,mixture performance and modeling of pavement materials,multi-scale mechanics,green and sustainable pavement,and intelligent pavement.Overall,this review paper is able to provide references and insights for researchers and engineers in the field of pavement engineering.

Investigation on the freeze-thaw damage to the jointed plain concrete pavement under different climate conditions

Freeze-thaw damage is one of the main threats to the long time performance of the concrete pavement in the cold regions. This project aims to evaluate the influence of the freeze-thaw damages on pavement distresses under different climate conditions. Based on the Long-Term Pavement Performance （LTPP） data base, the freeze-thaw damage generated by four different kinds of climate conditions are considered in this project： wet-freeze, wet-non freeze, dry- freeze and dry-non freeze. The amount of the transverse crack and the joint spalling, along with the International Roughness Index （IR/） are compared among the test sections located in these four different climate conditions. The back calculation with the Falling Weight Deflectometer （FWD） test results based on the ERES and the Estimation of Concrete Pavement Parameters （ECOPP） methods are conducted to obtain concrete slab elastic modulus and the subgrade k-value. These two parameters both decrease with service time under freeze condition. Finally, MEPDG simulation is conducted to simulate the IR/development with service year. These results showed the reasonable freeze-thaw damage development with pavement service life and under different climate conditions.