水泥固化砒砂岩强度与孔隙结构演变的灰熵关联分析

为了研究水泥固化砒砂岩孔隙结构生长发育的演变规律以及其对抗压强度的影响，通过孔隙特征参数和孔隙半径预测抗压强度，对不同养护龄期下不同掺量的水泥固化砒砂岩宏观力学性能和微观结构进行测试和分析，采用灰关联熵探讨了水泥固化砒砂岩的孔隙特征参数和孔隙半径对强度的关联程度，并建立孔隙结构与抗压强度的灰色预测模型。结果表明，水泥固化砒砂岩的横向弛豫时间T2谱均呈现

Grey entropy analysis of strength and pore structure evolution of cement-solidified Pisha sandstone

Abstract: Pisha sandstone is a kind of weakly cemented sandstone with loose structure and low diagenesis. In order to study the evolution of the growth and development of the pore structure of cement-solidified Pisha sandstone and its influence on compressive strength, the samples of cement-solidified Pisha sandstone with cement content of 4%, 7% and 10% were prepared, and their unconfined compressive strength and microscopic morphology were tested. The transverse relaxation time and pore characteristic parameters of samples with different curing ages were tested by nuclear magnetic resonance. According to the relationship between the transverse relaxation time and pore size, the pore radius of the three sets of patterns were converted and divided into four intervals: micro pores (0-0.1 μm), mesopores (>0.1-1 μm), macropores (>1-10 μm), and crack pores (>10 μm). The relationships between pore characteristic parameters and pore radius on strength of cement-solidified Pisha sandstone was analyzed by using the grey correlation entropy method, and the grey prediction model of pore structure and compressive strength was established. The results showed that the compressive strength of cement-solidified Pisha sandstone increased with curing age, and the hydrated gelling products ettringite (AFt) and hydrated calcium silicate (C-S-H) improved the internal pore structure of the sample through expansion filling and cementation. The transverse relaxation time spectrum of cement- solidified Pisha sandstone presented a