Virtual Concrete Dilatometer

The purpose of this form is to estimate the autogenous deformation of a concrete based on measurements performed on its component mortar and the application of the equations of Pickett^[1]. The user simply fills in the table below and provides the other necessary inputs such as volume fraction of coarse aggregate and elastic properties of the concrete and the coarse aggregate, and the table will be updated with the estimates for the autogenous deformation of the concrete.

---

Mixture Proportions and Properties

Coarse Aggregate Volume Fraction (0-1):

Coarse Aggregate Elastic Modulus:  GPa

Coarse Aggregate Poissons Ratio:

Time (h)	Concrete modulus (GPa)	Poisson ratio	Mortar deformation (uE)	Estimated concrete deformation (uE)	Computed exponent (Pickett)

---

Equations of Pickett

$$\epsilon_{concrete} = \epsilon_{mortar}(1-V_{CA})^n$$

$$n = \frac{3(1-v_{concrete})}{1+v_{concrete}+ 2(1-2v_{ca})\frac{E_{concrete}}{E_{CA}}}$$

---

1) Pickett, G., Effect of Aggregate on Shrinkage of Concrete and a Hypothesis Concerning Shrinkage, Paper 52-36, Journal of the American Concrete Institute, 581-590, 1956.

---

Questions or comments:

E-mail: dale.bentz@nist.gov