Bolivia has abundant pebbles, while the supply of crushed stone is limited and unstable. Thus, the resource utilization of local pebble as a coarse aggregate and the guarantee of concrete durability are the key scientific issues in the Sucre Highway Project. In this paper, a comparative analysis was conducted of the performance of crushed stone concrete and pebble concrete. Additionally, the impact of fly ash on the water permeability resistance of concrete was investigated. The results indicate that the apparent density, bulk density, and void ratio of pebbles are lower than those of crushed stone, and the aggregate gradation of pebbles is dispersed. The type of aggregate is the primary factor influencing the splitting tensile strength of concrete, with the main failure modes of pebble concrete being slurry cracking, aggregate crushing, and interface debonding. While aggregate and fly ash have a minor effect on compressive strength, they significantly impact flexural tensile strength; however, all concretes meet the requirements for extra-heavy, very heavy, and heavy traffic load levels. In terms of impermeability, fly ash effectively mitigates the negative impact of aggregate type on the impermeability of concrete. These findings support the application of pebble concrete in the highway project.

The development of high-performance aggregate is a key direction of sustainable concrete. One effective synthetic technology for producing artificial aggregates is hydrothermal synthesis. Using waste basalt mud from the construction of a low-carbon industrial park as a raw material further facilitates the utilization of solid waste resources. Therefore, this paper adopted the hydrothermal synthesis method to produce artificial aggregates developed from basalt mud (AABM). Subsequently, it was used to partially replace mechanical aggregate in the preparation of concrete with strength grad C30. The engineering properties of concrete prepared with AABM (C-AABM), including workability, densities, mechanical properties, and frost resistance, were investigated to assess the feasibility of using AABM as concrete aggregates. The results showed that the fluidity of C-AABM can be significantly improved by using AABM. The hardened C-AABM, prepared with 10 ~ 30 vol% AABM instead of mechanized aggregate, exhibited a dry density decrease of less than 5%, indicating the feasibility of using AABM for ordinary concrete. However, excessive AABM negatively affected the mechanical properties of the concrete. When the AABM substitution was no more than 15 vol%, the impact of AABM on the compressive strength and modulus of elasticity of C-AABM was less than 15%. Nevertheless, the performance of the concrete deteriorated dramatically with the addition of AABM under freezing conditions. As described, the primary engineering advantage of preparing C30 concrete with AABM is to improve the workability of the fresh matrix without significantly reducing the mechanical properties of the hardened concrete. It proves the viability of AABM as an alternative aggregate for ordinary concrete production.