Investigation of the effects of steam curing of concrete at different temperatures on cost and compressive strength by response surface methodology

DAVRAZ M., IŞILDAR N., KAPLAN A. N.

Construction and Building Materials, cilt.470, 2025 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 470
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1016/j.conbuildmat.2025.140589
  • Dergi Adı: Construction and Building Materials
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC
  • Anahtar Kelimeler: compressive strength, Prefabricated concrete, response surface methodology, steam curing, superplasticizer, unit cost
  • Isparta Uygulamalı Bilimler Üniversitesi Adresli: Evet

Özet

Superplasticizers enhance workability and strength at low water/cement ratios. However, research on the effects of superplasticizers on the properties of fresh and hardened concrete during steam curing is limited. In this study, the slump values of fresh concrete samples prepared with four different superplasticizers obtained from various construction chemical manufacturers and their compressive strengths after steam curing at three different temperatures, taking into account their unit costs, were investigated. A fixed water/cement ratio and slump value were targeted in the concrete mixes. After 4 h of steam curing, PF 65 was identified as the optimum superplasticizer, providing the highest compressive strength (18.5 MPa). Specimens with PF 65 were then subjected to steam curing at different temperatures (60, 70, and 80 °C). The compressive strengths and unit costs after curing were analyzed, and the optimum steam curing temperature was determined to be 60 °C. Subsequently, the effect of a setting acceleator (calcium formate) on strength was also examined. At 60 °C and 4 h of steam curing, the use of 2 % calcium formate increased compressive strength by approximately 10 %, while the unit cost of the concrete increased by 30 %. It was concluded that the setting accelerator was not beneficial in terms of cost/benefit. Finally, changes in strength related to water/cement ratios were investigated by reducing the mixing water while keeping the slump constant and by increasing the cement dosage while keeping the mixing water constant. Using a polycarboxylate-based superplasticizer (PF65) with a water/cement ratio of 0.42 (slump: 19 cm) and steam curing for 4 h at 60 °C, the compressive strength of the specimens was determined to be 25.6 MPa, and the unit cost was 40 $/m³, offering the optimum cost/benefit characteristics. Additionally, the experimental findings were statistically analyzed using the response surface method.