Supply of laboratory equipment for the single DepartmentsTechnology - Laboratory Road GDDKiA divided into parts Lot 1 - Supply of equipment kit for determining the characteristics of air pores
in the hardened concrete - 3 pcs .
Therefore one can conclude that when air pores are distributed more sparsely and their specific surface area is larger, then the structure is more homogenous.
But the question arises: does the air pore structure in hardened self-compacting concretes depend on the added superplasticizer?
Considering the above, the air pore structure of several self-compacting concretes made with additions of two most commonly used superplasticizers was examined.
The air pore structure in the four hardened 90-day old concretes was examined in a diameter range of 10-4000 [micro]m by means of a computer image analyzer Image Pro Plus 4.
r] and specific air pore surface a are higher for concrete C/[S.
This means that the air pore structure in concrete C/[S.
The above analysis of the porosity structure investigation results shows clearly that the air pore structure differs between the self-compacting concretes.
In order to illustrate the influence of air pore structure on the failure of the self-compacting concretes, diagrams of the dependence of the average relative levels of cracking initiating stress [[sigma].
an impermeable structure free from water capable of being frozen, and producing an appropriate system of air pores
not able to be completely filled with water, which, at the same time, will contribute to an improvement in the thermal properties of the material.
The soil has air pores
and volume space," said Falder.
Ryegrass seedling weights were significantly greater in non-poached compared with poached treatments, while the content of air pores
>60Bm in the top 40mm of soil was 10.
2006), the type of a superplasticizer is crucial on account of the size and proportions of air pores participation, obtained as a result of its functioning, although the time of hardening of concrete does make a difference to further changes of these proportions (Fig.
Research results of porosity structure show that air pores which are the effect of the functioning of a superplasticizer, depending on flowability of a mix, can have irregular shape or can also be regular, and because of their shape and size look similar to pores formed as a result of acting of an air-entraining admixture.
According to Phielleo's conception, the "flow length" index determines protected volume of cement paste by one air pore (Fig.