The effect of thermal pretreatment on the creep of hardened cement paste

✍ Scribed by R.L. Day; B.R. Gamble

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 616 KB
• Volume: 13
• Category: Article
• ISSN: 0008-8846
• DOI: 10.1016/0008-8846(83)90053-4

✦ Synopsis

Miniature, saturated, hardened cement paste specimens were pretreated for 2 days at various temperatures in the range 20-92°C. Specimens were then loaded for 6 days and unloaded; immediate, creep and recovery strains were monitored, as were changes in the microstructure --polysilicate and nitrogen $orption analyses were used for this purpose. For both young (28d) and mature (2.5y) specimens, thermal pretreatment resulted in significant changes in the microstructure; polysilicate content and average pore size increased while surface area decreased. In young specimens, the pretreatment resulted in a reduction in subsequent creep deformation; good correlation was found between creep and the polysilicate content at the time of load. The results for mature specimens showed a different trend; in these, pretreatment resulted in an increased creep response. Polysilicate measurements made before and after loading showed significant differences. In young specimens polysilicate content increased during loading. In contrast, depolymerisation appeared to result from loading mature specimens.