摘要 |
<p>The invention provides a concrete which comprises in parts by weight: 100 of Portland cement; 50 to 200 of a sand having a single grading with a D10 to D90 between 0.063 and 5 mm, or a mixture of sands (preferably two sands), the finest sand having a D10 to D90 between 0.063 and l mm and the coarsest sand having a D10 to D90 between 1 and 4mm 10 to 50 of a particulate substantially non-pozzolanic material having a mean particle size less than 15μm; 0.1 to 10 of a water-reducing superplasticizer; and 10 to 30 of water; which concrete is substantially free of silica fume; the said concrete having a compressive strength greater than 100 Mpa at 28 days.</p> |