PDF Publication Title:
Text from PDF Page: 007
of several FRC mixtures but, beyond 28 days of age, the fck values became nearly identical between plain and fibre reinforced concrete. When comparing FRC to the plain concrete, there was no substantial increase in the cylinder split tensile strength as gains below 10% were recorded at both ages of tested concrete of 28 and 90 days. The static flexural rupture modulus, fctm, (estimated from the load-controlled three point bending tests prisms) was 3 ÷ 14% higher for FRC than for plain concrete at the age of 28 days but the results from a larger number of specimens would be needed to provide statistical relevance to any claim that the static tensile strength of concrete is increased by HDPE fibres. Table 4: Mechanical properties for seven concrete mixtures (every value is the average from three specimens except fctm for which only one prism was load-tested). Concrete age plain Ø0.25mm fibres Ø0.40mm fibres Property Units [days] C1 C2 C3 C4 C5 C6 C7 Elastic modulus Ec GPa 28 Compressive strengths 24.2 24.5 24.9 25.2 24.2 25.9 25.5 fck (cube) MPa fck (cube) MPa fck (cyl) MPa Tensile strengths 28 33.2 34.3 31.1 32.3 31.0 31.0 30.5 90 38.1 40.1 38.4 37.7 37.2 37.7 38.7 28 23.3 26.2 24.1 23.4 24.1 26.6 23.5 fct (cyl) fct (cyl) fctm MPa 28 MPa 90 MPa 28 2.79 3.08 2.95 2.96 3.03 2.93 2.88 3.32 3.47 3.49 3.43 3.40 3.47 3.53 3.84 4.35 4.14 4.37 4.01 4.05 3.96 3.2. Post-cracking flexural strength of concrete Load-deflection plots in Fig. 6 show the effect of the recycled plain HDPE fibres on the post-cracking flexural capacity and ductility of the 500 mm long prisms subjected to the four- point bending. The loading was applied through the displacement-controlled power ram at the rate of 1 mm/min. While all prisms reached similar peak flexural loads in the region of Fcr ≈ 15.0 ÷ 16.0 kN when the corresponding deflections (over the 300 mm spans) were around 0.45 ÷ 0.50 mm, marginally higher loads were achieved with the smaller Ø1 = 0.25 mm diameter fibres. The post-cracking (residual) load levels, RL, achieved on prisms with Ø1 = 0.25mm fibres are in the region of 25 ÷ 45% of Fcr; these values are also higher than the residual load capacities achieved on prisms with the Ø1 = 0.40mm fibres which were between 13% and 32% of Fcr. As expected, the larger residual to peak load capacity ratio, RL/Fcr, was always achieved with the higher volume of added fibres. The post-cracking load level, RL is nearly constant within the deflection range dt < 5 · dcr where dt is the total deflection at the mid-point of the simply supported prism (Fig. 7) and dcr ≈ 0.50 mm is the deflection corresponding to the peak crack- opening load, Fcr. This is of significance in constitutive modelling for the non-linear FE analysis of HDPE FRC elements when the tension-stiffening effect of cracked concrete needs to be taken into consideration. 6PDF Image | Mechanical properties of concrete reinforced with recycled HDPE
PDF Search Title:
Mechanical properties of concrete reinforced with recycled HDPEOriginal File Name Searched:
concrete-reinforced-plastics.pdfDIY PDF Search: Google It | Yahoo | Bing
Development of a solar powered Electric Ship The Electricship website originally started off as a project to develop a comprehensive renewable, affordable, modular electric ship... More Info
Modular Boat Hull Composite The case for a unsinkable, modular composite hybrid boat hull... More Info
MS Burgenstock Hybrid Electric Catamaran Lake Lucerne Unique shuttle servicing Lucerne to the Burgenstock Resort... More Info
Ground Power Unit GPU Powered by Lithium Ion Batteries The goal of the Ground Power Unit is to provide a readily accessible, modular, ready-to-power solution for remote power... More Info
CONTACT TEL: 608-238-6001 Email: greg@electricship.com (Standard Web Page)