Quantitative evaluation method for workability of concrete based on bottom resistance analysis

A quantitative evaluation method for concrete workability based on bottom resistance analysis, comprising the following steps:

• step 1:
• carrying out a test for a bottom resistance of fresh concrete:
• placing a concrete container on a level platform, filling with the fresh concrete which has been already mixed evenly, removing a residual concrete from a surface of the container and vibrating, inserting a steel sheet into a bottom of the concrete, recording a displacement of the steel sheet and a corresponding time;
• step 2:
• drawing a curve of inserting velocity of the steel sheet over time:
• drawing a curve of displacement of the steel sheet over time based on the data of the displacement of the steel sheet and the corresponding time, and by deriving the curve of the displacement of the steel sheet over time to analyze the inserting velocity and time, then drawing the curve of the inserting velocity of the steel sheet over time;
• and
• step 3:
• quantitatively evaluating the concrete workability based on conditions of the bottom resistance:
• based on the curve of the displacement of the steel sheet over time determined by the test for the bottom resistance, evaluating the concrete workability by using a calculation model of general coefficient for the concrete workability to solve the general coefficient for the concrete workability,
• the calculation model of the general coefficient for the concrete workability is as follows by integral calculation with an interval of v>100 mm/s:
• W
• =
• ∑
• i
• =
• 1
• n
• ∫
• t
• i
• ⁢
• 1
• t
• i
• ⁢
• 2
• v
• ⁡
• (
• t
• )
• ⁢
• d
• ⁢
• t
• wherein W is the general coefficient for the concrete workability, n is a number of the interval, ti1 is a starting-point of the interval, ti2 is an end-point of the interval, i=1,2, . . . , n.