Effect of mix design on the size-independent fracture energy of normal- and high-strength self-compacting concrete

Abstract

Self-compacting concrete has a characteristic microstructure inherent to its specific composition. The higher content of fine particles in self-compacting concrete relative to the equivalent vibrated concrete produces a different fracture behavior that affects the main fracture parameters. In this work, a comprehensive experimental investigation of the fracture behavior of self-compacting concrete has been carried out. Twelve different self-compacting concrete mixes with compressive strength ranging from 39 to 124 MPa (wider range than in other studies) have been subjected to three-point bending tests in order to determine the specific fracture energy. The influence of the mix design and its composition (coarse aggregate fraction, the water to binder ratio and the paste to solids ratio) on its fracture behavior has been analyzed. Moreover, further evidence of the objectivity of the size-independent fracture energy results, obtained by the two most commonly used methods, has been provided on the self-compacting concrete mixes. RESUMEN:Influencia de la composición de la mezcla sobre la energía de fractura de hormigones autocompactantes de resistencias media y alta. Los hormigones autocompactantes tienen una microestructura interna inherente a su composición específica. Su mayor contenido de partículas finas, en comparación con hormigones vibrados equivalentes, provoca un comportamiento diferente en fractura que afecta a los principales parámetros de fractura. En este trabajo, se ha realizado una amplia investigación experimental del comportamiento en fractura de hormigones autocompactantes. Así, se han realizado ensayos de flexión en tres puntos para determinar sus propiedades de fractura sobre 12 hormigones autocompactantes de diferente composición, con resistencias a compresión que van desde 39 hasta 124 MPa (mayor que en otros estudios). De esta forma, se ha analizado la influencia de la dosificación del hormigón y su composición (contenido en árido grueso, relación agua-cemento y pasta-sólidos) sobre su comportamiento en fractura. Además, se ha validado, para hormigones autocompactantes, la objetividad de los resultados obtenidos mediante los dos métodos habitualmente empleados para la determinación de la energía de fractura.

Improving the Properties of Self-compacted Concrete with Using Combined Silica Fume and Metakaolin

“…In fact, Silica fume (SF) increases the cement cohesion and compressive resistance because it has a higher specific surface than metakaolin and cement, other studies confirmed these results and indicated that the use of metakaolin and Silica fume (SF) could increase the compressive resistance [9,[15][16][17]. Several experimental researches were conducted in recent years to investigate the effect of regular, volcanic, waste aggregate materials on different properties of self-compacted concrete [18][19][20][21]. Although there are acceptable studies about Silica fume (SF) and metakaolin, but there is only limited studied about the use of both of them simultaneously.…”

Analysis of the Utilization of Air-Cooled Blast Furnace Slag as Industrial Waste Aggregates in Self-Compacting Concrete

“…Five different concrete mixes have been manufactured in this work and are designated as mix I, II, III, IV, and V. Table 1 shows the mix proportions of each concrete and the constituents used. The method that was proposed by Deeb and Karihaloo [13] for self-compacting normal and high-strength concretes, which was successfully was used in numerous researches, designed the mix proportion [14][15][16][17]. The compositions of the mixes have kept the cement and superplasticizer dosage constant.…”

“…This diagram is an important fracture property, especially when a numerical analysis of the fracture behaviour of concrete is needed, since it could model the fracture mechanism of material [44]. In this work, it has used an inverse analysis method that is based on the non-linear hinge model described in [14,45,46] to determine the parameters that defines the bilinear tension softening diagram (see Figure 5). It is worth noting that a qualitative analysis of the influence of the microstructure in the fracture behaviour of concrete can be completed from their corresponding bilinear softening diagrams, as was carried out in other authors [14,15,47,48].…”

“…In this work, it has used an inverse analysis method that is based on the non-linear hinge model described in [14,45,46] to determine the parameters that defines the bilinear tension softening diagram (see Figure 5). It is worth noting that a qualitative analysis of the influence of the microstructure in the fracture behaviour of concrete can be completed from their corresponding bilinear softening diagrams, as was carried out in other authors [14,15,47,48]. The first steep linear branch of the softening diagrams is mainly a consequence of the microcracking process and the second linear branch is due to the frictional dissipation processes (e.g., aggregate interlock).…”

An Overview on the Rheology, Mechanical Properties, Durability, 3D Printing, and Microstructural Performance of Nanomaterials in Cementitious Composites

“…Another way to achieve a similar nucleation effect is to introduce 0.3% of C-S-H seeds into the pore medium, which promotes the formation of C-S-H bunches in the pore medium in place of the C 3 S stages [ 24 ]. On the other hand, the improvement in the pore medium accelerates the initial strength of mixtures, which can be quantified through microstructural investigations [ 25 ].…”