The influence of binder modification by means of the superplasticizer and mechanical activation on the mechanical properties of the high-density concrete
The influence of mechanical and chemical activation on the mechanical properties of high-density concrete and cement mortar has been studied. Portland cement optimum content necessary for apparent increase in the mechanical properties of cement composites has been determined. The size-content study of the mechanically and chemically activated cement has been undertaken. The heat emission development of the mortar based on activated binder has been studied by means of calorimetric measurements. It has been demonstrated that increase in concrete hardening after the activation originates from formation of the cement fine-crystalline structure. According to the elemental analysis data, hydrated calcium silicates (CSH) are developed in spherical globules.
1 Introduction
The mechanical properties of cement composites are dependent on the application efficiency of the binder`s properties [1-3]. A higher level of the efficiency can be achieved by various means of binder activation [4]. The hydration process quickens and the activity of the binder increases due to fine powdering of cement. Qian J. et al. [5] note that strength properties of fine-ground cements with milling fineness more than 5000 cm²/g do not differ at any age of the hardening period to some significant extent (the 2nd day hardening compressive strength increases by 5 – 10 %, but...