PSI - Issue 23

Lucyna Domagała / Procedia Structural Integrity 23 (2019) 342 – 347 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

347

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Despite the significant strength decrease, all four composites retained sufficient strength (5.4 MPa ÷ 9.0 MPa) to be still regarded as insulating-structural concretes.

4. Conclusions

Four tested insulating-structural composites, made of various lightweight aggregates revealed different resistance to high temperature. The density loss after heating at 400 o C ranged from 15 % to 26 % and was mainly determined by the type and content of porous aggregate. In the case of composites containing polystyrene granulate the density decrease was additionally caused by melting of the aggregate. The decomposition of cement paste seemed to affect the density loss only to a small extent. The decrease of compressive strength of concretes subject to the temperature of 400 o C reached 54 % and was ca two times lower for composites made of expanded glass than for those with perlite and polystyrene aggregates. In spite of the significant strength decrease, all four composites retained sufficient strength (> 3.0 MPa) to be still regarded as insulating-structural concretes. The achieved results indicate that the application of expanded glass aggregate concretes may be recommended for thin-walled insulating-structural elements applied at higher temperature up to 400 o C, while thin-walled concrete products containing polystyrene granulate should be used only at temperature lower than 200 o C due to the emission of harmful fumes at polystyrene melting.

Acknowledgements

The paper preparation was supported in part with the funds of the project EMMAT E-mobility and sustainable materials and technologies PPI/APM/2018/1/00027 financed by the Polish National Agency for Academic Exchange (NAWA)

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