claim: The Raven (2012 film) was released the United States in 2012.
evidence: Paver base is a form of aggregate used in the construction of patios and walkways whose topmost layer consists of mortarless -LRB- or `` dry-laid '' -RRB- pavers .. aggregate. Construction aggregate. patios. patios. walkways. walkways. mortarless. Mortar ( masonry ). pavers. Paver ( flooring ). The first layer in the construction of such a surface is called the subgrade -- this is the layer of native material underneath the intended surface .. subgrade. subgrade. It is usually compacted and stabilized .. If the final pavement is to have vehicle traffic , a layer of subbase of crushed stone or concrete must come next -- this layer will even out the subgrade and will bear the heaviest load from the pavement above .. subgrade. subgrade. subbase. Subbase ( pavement ). Next comes the base course -LRB- also called the aggregate base course or ABC -RRB- composed of crushed gravel varying from 0.75 in down to dust-particle size .. aggregate. Construction aggregate. base course. base course. It too is typically compacted and evened .. The next layer will be the paver base , composed of coarse sand and typically between 6 in and 12 in thick , depending on anticipated traffic .. sand. sand. The pavers are then laid on top of this , and then a uniform , fine-grained sand is poured between them .. pavers. Paver ( flooring ). sand. sand