| 摘要 |
<p>Thixotropy modifiers (especially for increasing thixotropic properties) and optionally polypropylene fibres are used as additives in free-flowing self-hardening concrete mixtures which already show dimensional stability under water before hardening and which, after hardening, show a compressive strength of 0.2-4.9 N/mm 2> after 28 days under water. Free-flowing, self-hardening mixtures comprise 10-90 (preferably 55-80) vol% of a filler (especially aggregate) with a grain size of 0-30 (preferably 0-8) mm, pozzolana and/or hydraulic binder(s) (especially Portland cement), water (W/B ratio = 1.0-5.0), air-filled pores (preferably up to 6 vol%) and additives (especially flow improvers), showing a density of more than 1.7 (preferably more than 1.9) and a compressive strength ( Onorm B3303) of 0.2-4.9 N/mm 2> after 28 days under water at room temperature. The additives include at least one thixotropy modifier (preferably for increasing thixotropy) in amounts of 0.05-15.0 (preferably 0.1-2.0) vol% and optionally polypropylene fibres; the mixture already shows dimensional stability under running ground water before hardening and without mechanical mixing, and the hardened mixture shows a compressive strength as above.</p> |
