Abstract: Blended cement compositions for mixture with aggregate and water to prepare cementitious products. Such blended cement compositions contain cement, calcined diatomaceous earth, calcined kaolin, fiberous material and reactive vinyl acetate co-polymers, with or without talc and/or bentonite or their functional equivalents. Admixtures for blending into cement to create such blended cements or their read-mix equivalents contain calcined kaolin, calcined diatomaceous earth, fiberous material and reactive vinyl acetate co-polymers, with or without talc and/or bentonite or their functional equivalents.