## 3 Results and Discussion
After analyzing the obtained experimental data on the effect of processing time on the strength and deformation characteristics of lightweight fiber-reinforced concrete, the following was established:  
* when processing a cement-sand mortar for 50 s, the value of the increase in cubic strength in compression was 4%; prismatic compression strength 8%; tensile strength in bending 16%; axial tensile strength 2%; ultimate deformations during axial compression did not change; ultimate deformations under axial tension increased by 1%; the value of the elastic modulus increased by 4%;
* when processing a cement-sand mortar for 60 s, the value of the increase in cubic strength in compression was 14%; prismatic compression strength 15%; tensile strength in bending 27%; axial tensile strength 16%; ultimate deformations during axial compression increased by 3%; ultimate deformations under axial tension did not change; the value of the elastic modulus increased by 7%;
* when processing a cement-sand mortar for 70 s, the value of the increase in cubic strength in compression was 21%; prismatic compression strength 22%; bending tensile strength 34%; axial tensile strength 16%; ultimate deformations during axial compression increased by 3%; ultimate deformations during axial compression increased by 3%; ultimate deformations under axial tension increased by 7%;
* when processing a cement-sand mortar for 80 s, the value of the increase in cubic strength in compression was 27%; prismatic compression strength 28%; tensile strength in bending 61%; axial tensile strength 32%; ultimate deformations during axial compression increased by 7%; ultimate deformations under axial tension increased by 9%; the value of the elastic modulus increased by 12%;
* when processing a cement-sand mortar for 90 s, the value of the increase in cubic strength in compression was 22%; prismatic compression strength 23%; tensile strength in bending 44%; axial tensile strength 22%; ultimate deformations during axial compression increased by 4%; ultimate deformations under axial tension increased by 5%; the value of the elastic modulus increased by 11%;
* when processing a cement-sand mortar for 100 s, the value of the increase in cubic strength in compression was 16%; prismatic compression strength 15%; tensile strength in bending 41%; axial tensile strength 16%; ultimate deformations during axial compression increased by 4%; ultimate deformations during axial compression increased by 3%; the value of the modulus of elasticity increased by 7%. Figure 6: Influence of the processing time of the cement–sand mortar in the VLA on the coefficients of the constructive quality of lightweight fiber-reinforced concrete. Figure 6 shows that the maximum values of the structural quality coefficients, calculated for various types of strength, are observed in lightweight fiber-reinforced concrete made using a cement-sand mortar, activated in the VLA for 80 s.  
Figures 7-13 show the correlation between the processing time in the VLA and cubic compressive strength, prismatic compression strength, tensile flexural strength, axial tensile strength, ultimate deformations in axial compression and axial tension of lightweight fiber-reinforced concrete, obtained as a result of the presented experimental research.