Ohio Rev. Code § 5525.19
Payment for the cost of the establishment, construction, reconstruction, improvement, maintenance, and repair of a highway under Chapters 5501., 5503., 5511., 5513., 5515., 5516., 5517., 5519., 5521., 5523., 5525., 5527., 5528., 5529., 5531., 5533., and 5535. of the Revised Code shall be made at intervals of not less than once a month as the work progresses, upon estimates made by the district deputy director of transportation in charge of the improvement and upon approval of the director of transportation. When an estimate is allowed on account of material delivered on the site of the work or in the vicinity thereof, but not yet incorporated therein, the material shall become the property of the state, but if the material is stolen, destroyed, or damaged by casualty before being used, or for any reason becomes unfit for use, the contractor shall replace the material at the contractor's own expense.
In addition to the estimates provided for by law, the director, under such conditions as the director prescribes, may allow and pay to a contractor a sum not exceeding the value of the material delivered by the contractor and safely stored at an approved site. When such estimate is allowed, the material on which it is allowed shall become the property of the state, but in case the material is stolen, destroyed, or damaged by casualty before being used, or for any reason becomes unfit for use, the contractor shall replace the material at the contractor's expense. A contractor may insure against loss or damage by fire or otherwise all materials on which estimates have been allowed.
R.C. §5525.19