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Indiana University Studies 



limestones which outcrop extensively in these counties. These 

 roads are for the most part in good condition, altho some of them 

 have been in use for a long time without any special care. 



The waste limestone resulting from the removal of the over- 

 bur ddh of Mitchell hmestone in many of the quarries is an ideal 

 road metal, and if transportation charges were reasonable its 

 use thru the State would give Indiana far better roads than exist 

 at the present time in many parts of the State. 



The Office of Public Roads of the United States Department 

 of Agriculture maintains a testing plant for the testing of road 

 materials, and many specimens have been tested, including 8 

 samples of limestone from Lawrence county and 5 samples of 

 limestone from Monroe county. All of these samples, altho 

 showing a low value of toughness, were high in their cementing 

 value and good in hardness and percentage of wear. The data 

 of these tests can be found in Bulletin No. 44 of the Office of 

 Public Roads. It is believed that Indiana has reached a new 

 period of road improvement, and it would be a good thing for the 

 quarrymen who are puzzling over methods of waste disposal 

 to see that the limestones of Lawrence and Monroe counties are 

 properly advertised and brought to the notice of officers in charge 

 of road construction thruout the State. 



The railroads that have tried to use the Oolitic limestone as 

 railroad ballast have been inclined to give an unfavorable 

 report of its usefulness. The roads which have used the Mitchell 

 as ballast report that it is very successful, but that the softer 

 Oolitic stone will not give a firm enough bed. The tests that have 

 been made with this stone have usually been over harder ballast 

 which had already been used. Under such conditions the softer 

 stone is held by the harder particles and ground as tho in a ball 

 mill by the jar of the passing trains. It seems probable that if 

 the entire roadbed could be made of the soft stone, it would tend 

 to cement in a solid mass and become in a sense monolithic. If 

 the material were ground reasonably fine before being placed in 

 position, then wet down and allowed to settle, the jarring action of 

 the passing trains would not tend to grind it fine as in the experi- 

 ments already mentioned. Much of the waste from some of the 

 quarries has been removed for ballast, but in most cases it was 

 given to the railroad for hauling it away. In most cases also the 

 operator loaded the material free of charge. 



Much crushed stone is used in concrete work. The strength 

 of the concrete is measured by the strength of the cement and so 



