Question

The exposure of conventional mixing in open bowl is about ___________ ppm in the breathing zone.

(a) 20

(b) 40

(c) 50

(d) 10

I had been asked this question by my college director while I was bunking the class.

This is a very interesting question from Hot Weather Concreting, Prepacked and Vacuum Cement topic in portion Special Concrete and Concreting Methods of Concrete Technology

Answer 1

Right choice is (d) 10

To elaborate: 10 ppm is the exposure value of conventional mixing in open bowl in the breathing zone. And the exposure limit lies in the range of 50-100 ppm in Europe.