碳纤维改性道面混凝土微波除冰效率研究

Study on Efficiency of Microwave Deicing on Carbon Fiber Modified Pavement Concrete

基于混凝土吸波发热特性的微波加热道面除冰是一种环保、经济的道面除冰方法,但普通混凝土受微波加热效率较低,这限制了微波除冰的效果。为解决混凝土吸波发热效率低的问题,通过在混凝土中掺入不同长度及掺量碳纤维材料的方法提高道面混凝土吸波发热效率,试验研究了不同碳纤维长度及掺量对吸波发热效率的耦合影响,采用自主研发的开放式微波除冰车和光纤温度传感器对试验技术进行改进,并对试验结果进行了理论推导和机理分析。结果表明:将一定量的碳纤维掺入混凝土中能够提升其吸波发热效率,提升幅度随碳纤维的掺量及长度的变化而变化,合理运用碳纤维对混凝土进行改性可以达到对路面进行微波除冰的目的;试件吸波发热的前期热量需要向下传导,温度上升较慢,热量传导平衡后,温升速率逐渐趋于一个定值,温度稳定上升;碳纤维改性混凝土有一定的温敏性,其电磁参数和导热参数随着温度变化而变化,相关参数的求解方程为超越方程;在一定范围内,试件的温升速率随掺入碳纤维长度及掺量的增大而升高,但当碳纤维掺量过大时,反而会抑制其吸波发热效率,碳纤维长度与掺量对混凝土吸波发热效率的影响具有复合作用,碳纤维掺量为2‰,长度为0.6 mm时,温升速率最高,可达0.68℃/s,较普通混凝土提高4.8倍。

Microwave heating pavement deicing based on the microwave absorption and heating characteristics of concrete is an environmental and economic pavement deicing method,but the microwave heating efficiency of ordinary concrete is low,which limits the effect of microwave deicing.In order to solve the problem of low microwave absorption and heating efficiency of concrete,the microwave absorption and heating efficiency of pavement concrete is improved by adding carbon fiber materials with different lengths and amounts into concrete.The coupling influence of different carbon fiber lengths and contents on microwave absorption and heating efficiency is experimentally studied.The experimental technology is improved by using the independently developed open microwave deicing vehicle and optical fiber temperature sensor,and the experimental result is theoretically derived and analyzed.The result shows that(1)Adding a certain amount of carbon fiber into concrete can improve its microwave absorption and heating efficiency,the increase range changes with the content and length of carbon fiber,and the rational use of carbon fiber to modify concrete can achieve the purpose of microwave deicing on pavement.(2)In the early stage of wave absorption and heating of the specimen,the heat needs to be conducted downward,and the temperature rises slowly.After the heat conduction is balanced,the temperature rise rate gradually tends to a fixed value,and the temperature rises steadily.(3)Carbon fiber modified concrete has certain temperature sensitivity,its electromagnetic parameters and thermal conductivity parameters change with the temperature,and the solution equation of relevant parameters is transcendental equation;(4)In a certain range,the temperature rise rate of the specimen increases with the increase of the length and content of carbon fiber,but when the content of carbon fiber is too large,it will inhibit its microwave absorption and heating efficiency.The length and content of carbon fiber have a composite influence on the microwave absorption and heating efficiency of concrete.When the content of carbon fiber is 2‰and the length is 0.6 mm,the temperature rise rate is the highest,up to 0.68℃/s,which is 4.8 times higher than that of ordinary concrete.