onc_artisan
The concrete would have achieved 50mpa
Close...was about 45 MPa from an original design spec of 25 MPa
onc_artisan
and likely had been treated with anti-carbonation solutions after cure, as well as used additives to prevent ingress during placement
Not in the 1930's when this reservoir was built...just bloody good concrete from an on site batch plant and no corners cut engineering... ...occasionally we see AAR due to the locally sourced river gravels which cause a few issues.