This　paper　deals　with　the　effect　of　the　aggregate　type　on　the　behavior　of　dam　concrete　(or　mass　concrete)　in　uniaxial　tension　and　compression　with　two　hypes　of　aggregates　by　full　size　specimens　of　450　x　450　x　900　mm　(18　x　18　x　35　in.)　for　tension　and　450　x　450　x　450　mm　(18　x　18　x　18　in.)　for　compression　and　by　standard　size　specimens　150　x　150　x　550　mm　(6　x　6　x　22　in.)　for　tension　and　150　x　150　x　150　mm　(6　x　6　x　6　in.)　for　compression,　respectively.　The　complete　stress-strain　responses　both　in　tension　and　compression　were　acquired　through　a　systematic　experimental　program.　Models　with　hyperbolic　form　were　proposed　to　estimate　the　basic　mechanical　properties　and　the　fracture　parameters　of　the　concretes　with　specimen　ages.　Relationships　between　the　tensile　and　compressive　strengths　were　established.　Theoretical　models　for　normalized　axial　stress-strain　curve　in　compression　and　for　normalized　axial　stress　versus　normalized　maximum　crack　width　curve　in　uniaxial　tension　were　proposed.　In　addition,　the　axial　stress-crack　width　curves,　fracture　energy,　and　brittleness　were　also　obtained　based　on　the　stress-deformation　curves.　It　was　found　that:　the　strengths,　modulus　of　elasticity　and　fracture　energy　increase　with　specimen　age;　the　specimen　size　and　maximum　aggregate　diameter　significantly　affect　the　fracture　energy,　peak　strain,　and　crack　width　of　concretes　in　uniaxial　tension;　and　the　performance　of　concrete　with　crushed　coarse　aggregate　is　higher　than　that　of　concrete　with　natural　coarse　aggregate.