142 CEMENT AND CONCRETE 



6) Does the job indicate that the forms were well 



made? 



7) If the forms were not well made, what was wrong 



with them? 



8) Why do poor foundations often cause cracks in con- 

 crete walls? 



9) Examine the foundation and note if care was ob- 



served in its preparation. 



10) Is the foundation well drained ? 



11) What is the effect of poor drainage under a founda- 



tion wall? Under a sidewalk? Under a road? 



12) What precaution should be taken in constructing an 



earth-retaining wall? 



13) If cracks have formed, were they due to lack of or 



insufficient reinforcement? 



14) Where should reinforcing steel be placed in such a 



wall? ' Why? 



15) Why should a wet or quaky mix be used where the 



concrete is reinforced? 



16) Write a brief statement about each piece of work, 



giving your opinion as to what should be done to 

 make a first-class job. 

 6) Examine concrete material, note the quality, etc. 



1) Examine a sack of cement. See if it is free from 



lumps and is fresh. 



2) Note the brand of cement examined. 



3) Note the condition of the bag. 



4) Why is it important to take care of the bags and not 



allow them to get wet? 



5) Examine available sand. See if it is clean, free from 



clay, coal or other organic matter. 



