Silane impregnation is divided into liquid (CFS-0471 isobutyltriethoxysilane CAS 17980-47-1) and paste (CFS-213 isooctyltriethoxysilane CAS 35435-21-3). Since silane is a chemical product, although it is sprayed on the surface, it is different from other construction methods such as architectural coatings and paints. Its construction process is as follows: concrete surface treatment → spraying sampling test → spraying operation → acceptance. The following is a brief description of the construction characteristics of silane impregnation combined with the actual construction of No.3 and No.4 drainage culvert of Ningde Nuclear Power Phase I Project.

(A) Surface treatment of components
(1) The drainage culvert is constructed in sections, and the design length of each section of box culvert is 20 meters to 22 meters, so the silane impregnation takes each section of box culvert as the construction section. After the concrete reaches the designed strength, the mold is demolished, and the silane impregnation can be carried out only after the age of the concrete reaches 28 days according to the specification.
2) Firstly, the surface of concrete should be cleaned, especially the horizontal surface, which has more debris due to the construction.
3) If there are defects such as honeycomb, pockmarked surface and cavity in the concrete after demoulding, it should be repaired, and if the shrinkage crack on the surface reaches 2mm wide, it needs to be repaired with special repair mortar. After repair, the concrete should be maintained according to the specification. Support the formwork with through-wall screws, the two ends of the cone after the removal of the vacant parts, to be repaired with special concrete repair emulsion mortar perfect.

(B) spraying sampling test
In the construction of the first section of the box culvert any wall test spraying about 5 square meters test area, witness sampling sent for inspection after passing, before the subsequent construction of a large area.
(1) Sampling time: at least 7 days after spraying sampling.
(2) Sample specification quantity: diamond drilling sample, diameter 5㎜, depth (length) 40±5㎜ of core sample. 3 groups of 6 in total.
(3) Test items: depth of impregnation, water absorption rate and the reduction effect of chloride absorption.