Relationship between pore structure and compressive strength of concrete: Experiments and statistical modeling

Abstract

Properties of concrete are strongly dependent on its pore structure features, porosity being an important one among them. This study deals with developing an understanding of the pore structure-compressive strength relationship in concrete. Several concrete mixtures with different pore structures are proportioned and subjected to static compressive tests. The pore structure features such as porosity, pore size distribution are extracted using mercury intrusion porosimetry technique. A statistical model is developed to relate the compressive strength to relevant pore structure features.

Research on Strength Prediction Model of Sand-like Material Based on Nuclear Magnetic Resonance and Fractal Theory

“…Gao [23] combined multiple linear regression with grey correlation analysis, and studied the influence of pore size distribution and porosity on the compressive strength of materials in mortar. Bu [24] obtained the pore volume and pore size distribution of concrete specimens with different proportions by mercury pressing experiment, then established the statistical model of microscopic characteristics (porosity and pore size distribution) and compressive strength. At present, experimental studies on the microstructure (porosity, pore size distribution) and macroscopic mechanical properties of porous materials are mainly analyzed by mercury intrusion test, while the mercury intrusion test not only causes damage to the internal pore structure but also can not reflect 100% of the pore space distribution information adequately.…”

Modification Effects of Carbon Nanotube Dispersion on the Mechanical Properties, Pore Structure, and Microstructure of Cement Mortar

“…Dispersants introduce air bubbles in cement-based materials, which leads to increased porosity and is disadvantageous to the development of material strength. In addition, a few scholars have focused on the effect of CNT dispersants on the cement matrix and have found the properties of cement are closely related to the pore structure [27][28][29].…”

Thermo-Mechanical Properties of High-Performance Natural Pozzolan Concrete.

“…As the porosity increases, the mechanical strength of a concrete decreases [5]. This phenomenon has been confirmed by JBu and Z Tian [6] on the compressive strength of light concretes, which is a decreasing function of the volume fraction of aggregates. The second originality of this work concerns the specific characteristics of natural pozzolana concrete.…”

“…it is an expression of the form: Vap = XP + const because C, , f and V prove constant. Since e represents the void index of the mixture, as follows: Vap = Vvide + Vmaterial = e + 1 Hence the relation (3) becomes: e = v / (f -1 -CV) + CV (5) e = (P/) (f -1 -CV) + CV (6) It can be seen that the value of f is close to 2. Therefore, the substitution of the large granulate for the fine granulate tends to decrease the apparent volume corresponding to the void ratio of the mixture studied.…”

“…The combination of relations (5) and 7leads to the existence of a binary mixture where the apparent volume (the void ratio) is maximal. In theory, this volume must be at the intersection of the two lines formed by the relations (6) and (8).…”