Compacted Chalk Putty–Cement Blends: Mechanical Properties and Performance

Abstract

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Strength and stiffness of compacted chalk putty–cement blends

“…The chalk soil was collected from St Nicholas at Wade, Kent (United Kingdom). Bialowas et al [13] and Consoli et al [34] investigated chalk from the same location. In addition, this site was recently used for pile and cone penetration tests as reported by [17,19,20,36,41].…”

“…However, no dosage formulation relating to the mechanical behaviour of compacted chalk-cement mixtures is available and no studies determining the tensile strength of chalk putties, the stiffness evolution during the curing time and the design parameters such as friction angle and cohesion intercept exist. This paper presents a set of new experimental result to fill this knowledge gap, and the results are analysed in conjunction with those previously published by Consoli et al [34]. Interpretation of the experimental results uses the methodology introduced by Consoli et al [26,27] and further explored by Consoli et al [29,31,32] and Diambra et al [37], based on the dimensionless ratio between porosity and volumetric content of cement (g/C iv a ), where the porosity (g) is defined as the ratio of volume of voids to the total volume of the specimen, the volumetric content of cement (C iv ) is defined as the ratio of volume of cement to the total volume of the specimen and a is an exponent depending on the material types and was found to be equal to 0.28 for soils containing fines and Portland cement.…”

“…The frequencies free of near-field effects (f) were calculated according to ASTM D2845 [3] considering a value of the wavelength number (R d ) of at least 3.3. Considering the tip-to-tip bender distance (d) of 0.079 and using the wave velocities (V s ) determined by Consoli et al [34] in analogue cement chalk-putty blends using the Ultrasonic Pulse Velocity (UPV) system (note that k = V s / f), frequencies higher than 30 kHz would lead to R d [ 3 and thus free of near-field effects.…”

“…6 Variation in splitting tensile strength (q t ) with adjusted porosity/cement index for chalk putty-Portland cement blends for 7 days of curing q u = 1.37 x 10 9 (η/C iv 0.28 ) -3.87 , R² = 0.983 q t = 3.53 x 10 9 (η/C iv 0.28 ) - Fig. 7 Results of unconfined compressive strength (q u ) [34] and splitting tensile strength (q t ) for chalk putty-Portland cement blends for 7 days of curing (Fig. 4).…”

“…Recent research by Consoli et al [34] also reveals the advantages of using Portland cement for the improvement in compacted chalk putties, resulting in an increase in the unconfined compressive strength, initial stiffness after 7 days of curing time and increased durability. However, no dosage formulation relating to the mechanical behaviour of compacted chalk-cement mixtures is available and no studies determining the tensile strength of chalk putties, the stiffness evolution during the curing time and the design parameters such as friction angle and cohesion intercept exist.…”