孔隙特征对机制砂自密实轻骨料混凝土强度的影响规律

为了研究微观孔隙特征对机制砂自密实轻骨料混凝土力学性能的影响规律，配制了强度等级为C30、C40、C50的机制砂自密实轻骨料混凝土，测量了其养护3、7、14、28 d时的立方体抗压强度、劈裂抗拉强度以及微观孔隙特征，研究了机制砂自密实轻骨料混凝土的早期强度发展规律、内部孔隙演变规律以及各影响因素与机制砂自密实轻骨料混凝土28 d抗压强度之间的灰熵关联度。结果表明：机制砂自密实轻骨料混凝土随强度的升高，14～28 d的强度发展速率越大；随养护龄期增长，混凝土中无害孔占比增加，多害孔占比减少，强度升高；虽然在各类型孔隙中，无害孔与多害孔体积占比最大，但从灰熵关联结果来看，与28 d抗压强度关联最大的是有害孔的占比，其次是无害孔占比。因此实际工程中，在制备机制砂自密实轻骨料混凝土时，应多考虑如何降低有害孔占比。

The influence of Pore characteristics on the strength of manufactured sand self-compacting lightweight aggregate concrete

In order to study the influence of microscopic Pore characteristics on the mechanical properties of machine-made sand self-compacting lightweight aggregate concrete, this paper prepared machine-made sand self-compacting lightweight aggregate concrete with strength grades of C30, C40, and C50, and measured its curing for 3d, 7d, and 14d. , 28d cube compressive strength, split tensile strength and microscopic Pore characteristics, studied the early strength development law, internal pore evolution law of machine-made sand self-compacting lightweight aggregate concrete, as well as various influencing factors and machine-made sand self-compacting lightweight bone Correlation between 28d compressive strength of aggregate concrete. The results show that as the strength of machine-made sand self-compacting lightweight aggregate concrete increases, the strength development rate from 14d to 28d is greater; As the curing age increases, the proportion of harmless holes in the concrete increases, the proportion of harmful holes decreases, and the strength increases; although among the various types of pores, the volume of harmless pores and harmful pores account for the largest proportion, but from the gray entropy From the correlation results, the largest correlation with 28d compressive strength is the proportion of harmful pores, followed by the proportion of harmless pores. Therefore, in actual engineering, when preparing machine-made sand self-compacting lightweight aggregate concrete, more consideration should be given to how to reduce the proportion of harmful holes.