Exhibit 23.3 [Letterhead of Schneider Downs] CONSENT OF INDEPENDENT ACCOUNTANTS We consent to the inclusion in this registration statement on Form S-4 (Registration No. 333- ) of our report dated September 8, 1999, on our audits of the financial statements and financial statement schedules of Commercial Stone Co., Inc. and Commercial Aggregates Transportation & Sales, L.P. We also consent to the references to our firm under the caption "Experts." /s/ Schneider Downs & Co., Inc. Pittsburgh, Pennsylvania March 13, 2000