碱渣掺量对不同龄期下半刚性再生基层力学性能研究

Effect of Alkali Slag Content on Mechanical Properties of Semi-rigid Recycled Base Course at Different Ages

为了得到碱渣掺量对刚性再生基层不同龄期下力学性能的影响,考虑不同的碱渣用量,通过养护龄期为7、28、90、180 d下的无侧限抗压强度试验和室内抗压回弹模量试验对比分析不同体系间的差别。结果表明:随着养护龄期的增加,各个碱渣掺量下半刚性再生基层的无侧限抗压强度和抗压回弹模量均不断增大;随着碱渣掺量的增加,二灰稳定半刚性再生基层在养护龄期的前28 d无侧限抗压强度和抗压回弹模量不断增大,且在碱渣掺量小于3%时,增加量较大;在养护龄期超过28 d后,随着碱渣掺量的增加无侧限抗压强度和抗压回弹模量逐渐减小,且在碱渣掺量超过3%时,减小量增大,最终小于不掺碱渣的无侧限抗压强度和抗压回弹模量;在保证力学性能最佳的情况下,碱渣代替石灰的最佳掺量范围为1%~3%。

In order to obtain the effect of the amount of alkali slag on the mechanical properties of the rigid regenerated base layer at different ages,the different amount of alkali slag was considered.Through the unconfined compressive strength test and indoor compressive rebound modulus test under the curing age of 7,28,90 and 180 days,the differences between different systems were compared and analyzed.The results show that with the increase of curing age,the unconfined compressive strength and compressive rebound modulus of the semi-rigid regenerated base layer of each alkali slag content increase continuously.With the increase of alkali slag content,the unconfined compressive strength and compressive rebound modulus of the stable semi-rigid regenerated base layer increase continuously during the first 28 days of curing age,and the amount of increase is larger when the alkali slag content is less than 3%.After 28 days of curing age,the unconfined compressive strength and compressive rebound modulus gradually decrease with the increase of alkali slag content,and the amount of reduction increases when the amount of alkali slag exceeds 3%,which are finally less than the unconfined compressive strength and compressive rebound modulus without alkali slag.Under the condition of ensuring the best mechanical properties,the best dosage range of alkali slag instead of lime is 1%~3%.