CHAPTER XIV 

 'FORMS FOR CONCRETE; CURING CONCRETE 



125. Necessity of Forms. The plasticity of concrete, 

 and the readiness with which the material can be adapted to 

 all shapes and sizes of construction, which are two of the chief 

 merits of the material, make necessary the use of forms in 

 connection with it. 



126. Importance of Form Construction. The design 

 and construction of forms is one of the most serious problems 

 of concrete work. As a rule, on small work, the expense of 

 the forms is from one-fourth to one-half of the total cost of 

 the work in place. Many people do not appreciate this fact 

 and neglect the forms with the result that the finished work is 

 of poor quality, or else the forms have cost too much. The 

 shape, dimensions and finish of the work all depend on the 

 forms, and it is not possible to do good concrete work with- 

 out good forms. 



127. Earth Forms . In foundation walls, where care has 

 been observed in excavation and the earth stands up prop- 

 erly, it can be used. Earth can be used also in making well 

 tops, etc., where the work can be fashioned out in the clay. 

 The earth must be wet down thoroly to keep it from absorb- 

 ing too much moisture from the concrete. A combination of 

 wood and clay can be used. Molds of wet sand are used in 

 ornamental work. Frequently, colored sands are used for 

 this purpose, providing both the finished surface and color to 

 the concrete. 



131 



