Mendes Caldeira Building

Mendes Caldeira Building

The Loizeaux family, which has blasted its way to the top of the demolition business in the U.S. (ENR 8/10/72 p. 24), last week outdid itself by bringing down a modern, 32-story building in downtown São Paulo, Brazil with a single blast. It had to make way for a large station for the city's rail transit system, already under construction on the same block.

Controlled Demolition, Inc. (CDI), Towson, Md., run by Jack Loizeaux, his wife Freddie and sons Mark and Douglas, placed nearly 1,000 lb. of explosives in the heavily reinforced concrete structure which was only 12 years old. "We put 777 charges on 11 floors, many more floors than is usual, to ensure that the building would come down safely," says Mark Loizeaux. "We were afraid even to make test shots because of the tremendous interdependency of structural elements."

He says the job was complicated not only by the modern design of the 361-ft. high structure but because one wall was solid, which could have caused the structure to fall sideways rather than crumbling straight down into the 95-ft. deep basement. Also, there were stiff restrictions on where the 5,700 cubic yards of debris could fall because of the proximity of a plaza and the station structure under way. On 2 sides, it had to fall virtually within the building lines, and on the other two sides, within 20 and 33-ft of the lines.

There was some skepticism that the job could be done safely. According to Mark Loizeaux, the highest building previously demolished with explosives was 22 stories. Some local engineers openly expressed doubts, one Brazilian explosives producer refused to bid on the explosives order for fear the scheme would end in disaster, and the priest in the nearby Cathedral da Se prayed that the 58 x 90-ft building would come down safely.

Though officials tried to keep the date and time of the blast secret, word leaked out that it was to be 7 a.m. Sunday, November 16th. By 3 a.m. that day, surrounding streets were jammed by thousands of curious Paulistas. The blast went off without a hitch at 7:32 and, as the cathedral bells tolled heavily, the North American dinamitodores sealed their reputation by retiring to a tavern to buy their crew beer.

He estimates that without blasting it would have taken at least 6 months, working 3 shifts, to demolish the building and the cost would have been much more than CDI's $270,000 subcontract with the Brazilian prime contractor, TRITON.

Officials in both São Paulo and Rio de Janeiro said after the blast that they may use the technique to clear other structures. They are trying to speed construction of the rail transit systems in both cities because of sharply increased petroleum prices.