白云质鲕粒灰岩的混凝土碱碳酸盐反应膨胀行为

Alkali carbonate reaction behavior of oolite sparite dolomitic limestones

研究了具有类斑状结构特征的白云质亮晶鲕粒灰岩作为骨料的混凝土柱在150℃压蒸时的碱碳酸盐反应膨胀行为及其膨胀开裂特征。结果表明,白云质亮晶鲕粒灰岩的岩相结构实际上是类斑状结构与镶嵌亮晶基质的复合。呈类斑状结构、鲕粒内的基质为泥晶方解石的白云质亮晶鲕粒灰岩,显示潜在高AAR膨胀性,膨胀由ACR反应引起;基质是粒状亮晶方解石的白云质亮晶鲕粒灰岩显示弱ACR膨胀性;白云质亮晶鲕粒灰岩的开裂特征与岩石的复合岩相结构特点相对应,膨胀裂缝起源于鲕粒内部的白云石密集区。

The ACR expansive behaviors and relative crack characters of oolite sparite dolomitic limestones with a similar porphyrotopic texture have been explored while autoclaved at 150 ℃ .The results showed that the texture of oolite sparite dolomitic limestones is composed of porphyrotopic texture and mosaic sparite matrixes.The oolite sparite dolomitic limestones with a similar porphyrotopic texture and argillaceous calcite matrix are of potentially AAR active aggregates.This expansion is resulted from ACR rather than ASR.Comparatively, the oolite sparite dolomitic limestones with a similar porphyrotopic texture and sparite calcite matrix are of poor ACR.The crack character of this aggregates are related with their micro-textures, and the cracks origins from the dense dolomite regions within the oolites.