In this post we will discuss important requirements that control almost all specifications for ready mixed concrete industry as per ASTMC94/C. This is the pre-requirements for providing specifications for almost all parameters of ready mixed concrete. These requirements not only used in ASTMC94/C but also in other specifications related to concrete quality , batching and other standards related to concrete in ASTM standard.
In describing these requirements we have to know some terms related to concrete uniformity requirements. First we will learn about coarse aggregate content. We have to go through several posts to complete defining uniformity requirements of concrete. We have to know these requirements to understand strength, sampling and testing, mixing and delivery and all other specifications.
Coarse aggregate content:
This term is expressed in percentage and washout test is used to determine this.
The relation provided below defines the coarse aggregate content.
Here, p=mass of coarse aggregate in percentage of concrete mix
c= this is the mass of that aggregate retained by the 4.75 mm(No.4) sieve, provided that all finer materials than that sieve must be washout from the fresh concrete. The mass of aggregate must be in kg(lb) in standard surface dry condition.
b=this is measured in mass per unit volume container kg(lb). This is the mass of fresh concrete sample.
We will learn, mass per unit volume of air free mortar in the very next post. We will show some expression, to understand this. We will publish this post in a series for having sequential reading for you, dear reader.