By stating density, I mean to say specific gravity in simplest way.
Specific gravity of the material do impact on the volume of the concrete produced, in case when the concrete production is done by weight batching process.
At the time of concrete mix designing, the weights of the each aggregates are decided base on their specific gravity.
Specific gravity is the ratio of per unit volume of material compared with same unit volume of water (stating it with unit of kg/cum does not make any difference like, aggregate having specific gravity of 2.9, I could say aggregates weights 2900 kg per cum in its purest form without any voids in it, but as its a ratio in mathematical calculations kg and cum get removed).
crush aggregates when taken as cum quantity, it will weight less due to presence of voids in it, if we compare it with same aggregate / rock which is in size of 1m x 1m x 1m.
example - I have to put 750 kg of 20 mm aggregates in concrete. if its specific gravity becomes low due to higher porosity or voids in it. the volume which it makes to same weight will get increase and will make my concrete more than a cum for same mix design. same way if its specific gravity increases my volume will become less for same required weight of aggregate in mix, this will result into less volume of concrete.
Heavy weight concrete is produced by using heavy aggregates where the volume of the concrete is same but weights of aggregates are more.
so changes in specific gravity of aggregates do impact on the volume of concrete produced with it.