All materials furnished, unless otherwise specified, must be of a quality equal to the best of its respective kind and any must meet with the approval of the urban county engineer; and any work or material not in accordance with the specifications, or damages from any cause before the completion or acceptance, shall be rejected by the engineer and ordered acceptably replaced.
In case the contractor shall refuse to begin, after written notice from the urban county engineer to remove such material or repair such rejected work within twenty-four (24) hours, the same may be removed and replaced by the urban county government at the contractor's expense.
The contractor shall, whenever required, furnish to the urban county engineer samples of any materials proposed to be used by him. Where samples fail to stand required tests, cost of same must be borne by the contractor; otherwise they shall be included in the cost of such construction and charged to abutting property.