CONTENTS 7 



CHAPTER XII. PROPERTIES AND USES OF CEMENT . 115 



105. Properties. 106. Mortar. 107. Definition of concrete. 108. 

 Aggregates. 109. Presence of rotten or soft pebbles in the gravel. 

 110. Presence of dirt in the aggregate. 111. Vegetable matter in 

 sand. 



CHAPTER XIII. PROPORTIONS AND MIXTURES; HAND- 

 LING OF CONCRETE ...... 120 



112. Proportions. 113. Requirements of good concrete. 114. 

 Standard mixtures. 115. Common errors in proportioning con- 

 crete. 116. Determining quantities for a job. 117. Require- 

 ments of good mixing. 118. Hand-mixing. 119. Procedure in 

 hand-mixing. 120. Machine-mixing. 121. Consistency of mix- 

 tures. 122. Placing of concrete. 123. Three methods of placing 

 concrete. 124. Handling concrete. 



CHAPTER XIV. FORMS FOR CONCRETE; CURING CON- 

 CRETE 131 



125. Necessity of forms. 126. Importance of form construction. 

 127. Earth forms. 128. Cast, wrought or galvanized iron forms. 

 129. Wood forms. 130. Requirements of a good form. 131. Use 

 of old lumber for forms. 132. Sharp corners in forms. 133. Re- 

 moving forms; care of forms. 



CHAPTER XV. REINFORCING CONCRETE ; CEMENT WORK- 

 ING TOOLS 135 



134. The principle of reinforcing. 135. Compression and tension 

 in beams. 136. Kinds of reinforcing. 137. Use of scrap iron for 

 reinforcing concrete. 138. Tools for concrete work. 



CHAPTER XVI. PROJECTS IN CONCRETE CONSTRUCTION 140 



139. Study of concrete construction and concrete materials. 140. 

 Molded concrete. 141. Sidewalk and floors. 142. Constructing 

 a door step. 143. Hot-bed, foundation wall, etc. 144. Construct- 

 ing fence post. 145. Constructing a circular stock tank. 



CHAPTER XVII. SUPPLEMENTARY CONCRETE PROJECTS 166 



146. Constructing a garden or lawn roller. 147. A hog trough. 

 148. Engine or machine foundation. 149. Cistern or shallow well 

 top. 150. Manure pit and cistern. 151. Feeding floor. 152. 



