*2.1. Materials*

The vegetal materials used in this research were: ash from corn cobs of quality A and quality B, and ash from sunflower stalks of quality A and quality B. The developed and analyzed compositions were as follows:

	- With corn cob ash of A quality, as 2.5% and 5% replacement of cement volume (CCA1A, CCA2A),
	- With corn cob ash of B quality, as 2.5% and 5% replacement of cement volume (CCA1B, CCA2B),
	- With sunflower stalk ash of A quality, as 2.5% and 5% replacement of cement volume (SSA1A, SSA2A),
	- With sunflower stalks ash of B quality, as 2.5% and 5% replacement of cement volume (SSA1B, SSA2B).

The reference composition, RC, of 30/37 strength class, was realized for river gravel (sort 4–8 mm), sand (sort 0–4mm), cement Portland CEM II/A-LL42.5R type (notations according to EN 197-1:2011) [30] (HeidelbergCement Romania, Bucharest, Romania), superplasticizer additive based on polycarboxylateter (2% of binder), and water, according to NE 012/1-2007 [31].
