Tools and Machinery for Concrete Work

TOOLS AND MACHINERY FOR CONCRETE WORK With the skill and ingenuity characteristic of American enterprise in general, designers and inventors have developed a great variety of spe cial tools, machines, and devices for accomplish ing the different operations necessary in the mix ing, handling, and working of concrete. In addi tion to numerous hand-operated tools, the list includes crushers and grinders; screens and sep arators; mixers; automatic measuring devices for water, cement, and aggregates; automatic and pneumatic tampers; engines for power; hoists; elevators; wheelbarrows; dump buckets and cars; machines for making blocks, sills, posts, brick, tile, shingles, etc. Many typical examples of these tools and machines are illus trated in Figs. 15 to 26 and Plates 3 to 25.

The selection of the equipment necessary will depend on considerations of economy and effi ciency; and these, in turn, will be found to de pend on the size of the job, on the quantity to be mixed per day, and on local conditions peculiar to the work in hand. Each job, particularly on

large work, constitutes a problem by itself, call ing for careful analysis of details.

246 In general, it may be said that the plant should be located as near as possible to the place of depositing the concrete; uninterrupted facili ties for handling materials, charging mixers, and distributing the concrete should be provided; the cycle of operations should be simplified as much as possible, and systematically maintained; ma chine parts should in all cases be capable of ready duplication to prevent delays from break downs or wearing out of parts; a plant should be adapted not only to the original job for which it is selected, but to subsequent work of other kinds; and, on small jobs, to depend on hand labor is usually more economical than to invest large sums in machinery.