PSI - Issue 45

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Huailiang Chen et al. / Procedia Structural Integrity 45 (2023) 104–108 Huailiang Chen et al. / Structural Integrity Procedia 00 (2019) 000 – 000 where is the ratio of compressive strength of CRM and control mortar, is the volume ratio of rubber to the sample, = 2.66%, 5.31%, and 7.97% respectively for CRM6, CRM12, and CRM18 after converting the sand replacing ratio of 6%, 12% , 18% to sample volume ration. Δ is the increased porosity of CRM over the control mortar. The values of Δ for CRM6, CRM12, and CRM 18 are 0.55%, 1.1%, and 1.65%, respectively, which were obtained from experimental tests performed in the UniSA structural lab. The theoretical results for the compressive strength of the CRM including increasing air content could be calculated using Eq. (1). The comparison between the test and mesoscale simulation are compared in Fig.2. The differences between the test values and theoretical results of CRM6, CRM12, and CRM18 are 4.03%, 2.14%, and -4.71%, respectively. In numerical analysis, as the rubber content increases from 0% to 6%, the compressive strength of CRM reduces by 26%, then every 6% increase in rubber content will lead to a 10%-12% decrease in compressive strength. 107

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Theoretical results of CRM Test results of CRM

60.17

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60.39

55

50

44.72

45

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38.75

42.99

Compressive strength(MPa)

37.93

33.04

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31.48

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0%

6%

12%

18%

24%

Rubber percentage(%)

Fig. 2. Comparison of CRM specimen results obtained from experiment and mesoscale simulation.

4. Conclusion In this paper, a pore-based mesoscale model is proposed to evaluate the compressive strength of rubber mortar and the numerical results agree well with experimental tests with the maximum error within 5%. Numerical results show that the addition of rubber particles decreases the compressive strength of CRM. Conclusions from the above research are as follows: (1) The compressive strength reduction rate of CRM is mainly affected by the rubber content. The test results show that every 6% increase in rubber content results in an average 15.03% decrease in compressive strength. (2) The rubber particle size mainly affects the range of compressive strength variation of CRM. It is easier to make smaller-sized rubber particles distribute evenly in the sample and ensure that the strength of different specimens varies within a small range. (3) The air content of CRM is higher than the reference samples. The increase in CRM porosity should be considered when performing mesoscale analysis of CRM samples. Rubber particles and pores have similar effects on CRM strength.