Application of soil mortar into a cavity, e.g. a hole in a road or a pavement, involves meting and mixing soil mortar and a setting and hardening accelerator in an endless screw conveyor, and pouring the mixture into a cavity

摘要

Soil mortar and a setting and hardening accelerator are mixed in an endless screw conveyor (13), and the obtained mixture is poured by gravity through a loading chute (14, 28, 30) into a cavity (8) Filling a cavity (8) in, e.g., a road or pavement with soil mortar involves adding at least one setting and hardening additive to the soil mortar, and discharging the soil mortar from a vehicle that conveys the treated soil mortar to the vicinity of the cavity. The process involves: forming a first material comprising the soil mortar and moving it towards the cavity; forming a second material comprising the setting and hardening accelerator and moving it in the direction of the first material; mixing the first and second materials to obtain a third material; and introducing the third material into the cavity (8) by gravity. The amount of the second material is a function of the amount of first material in order to adjust the proportion of the setting and hardening accelerator in the third material. The soil mortar is based on Portland cement, and the accelerator is based on calcium aluminates. The Portland cement does not contain mineral additives such as fly ash or filler. The setting and hardening accelerator includes at most 1% C12A7, and is in the form of a powder, or a grouting liquid containing hardening inhibitors and, optionally, dispersants. Preferably, the cement comprises around 100 kg/m3 cement, a water/cement ratio of around 2, solely sand whose granulometry is at most 4 mm, and an air-entraining additive that provides an air content of around 15-25% of the total volume. The fluidity of the third material is high enough to allow the mixture of the soil mortar and the setting and hardening additive to be self-coating, i.e. it flows freely into the cavity (8) and fills it completely without leaving significant voids. An Independent claim is given for an installation for implementing the invented process.