Use of volcanic ash based aggregates for the design of rigid pavements in road projects at 2160 m a.s.l.

Volcanic ash is a pyroclastic material created by volcanic events. It is composed of small fragments of friable whitish fine-grained siliceous lavas. It can have different degrees of cementation, brittle type, so it can be identified in the category of collapsible soils. This research aims to evaluate the use of marginal aggregates containing volcanic ash for the design of a hydraulic concrete slab, which will be tested with the results of the bending and compression modulus. The results show that fine aggregates without volcanic ash do not comply all the requirements stablished by the Peruvian standard (EG-2013) from the highway manual. However, the American Concrete Institute (ACI) incorporates exceptions for particular conditions of aggregates, making it possible to use them based on compliance with the required strength and durability. The design of a concrete mixture for a theoretical resistance of f'c=280 kg/cm2 was planned. However, when the specimens were tested after 28 days of being cured,an f'c=380 kg/cm2 was obtained. This is because there is a close positive relation between the volcanic ash and the Puzolánic cement used for the mixture.