water treatment related question-about HDPE pipe

[marokki]

I have got two questions
1.How do we connect HDPE(high density poly-ethylene)pipe to brick masonry inspection chambers having masonry thickness 8.5" or 210mm-the joint should be leak-proof
2.An ordinary connection with out flange-joints filled with cement mortar(1:2 ratio) and also concreted (1:1.5:3) was found to have leak.How to rectify this problem?. [sig][/sig]

 

[ChrisWiid]

Dear Marokki

I have used a HDPE liner which is cast into the inside surface of the manhole. This enables you to weld the incoming pipe, to the liner, while still retaining the structural attributes of the manhole. A bit more costly but waste liquid manholes are things you do not want to have trouble with.

Another plan is to use a large diameter HDPE pipe as a manhole. In this way welding again becomes easy and the chemical integrity of the mahole is excellent

regards

Chris Wiid

South Africa [sig][/sig]

 

[TwoCents]

You can probably get an acceptable seal by using an expansive hydraulic cement (various products sold as "crack filler", "patching cement" or "anchoring grout&quot instead of the ordinary cement mortar and concrete that you've already tried. These cements/grouts typically have only fine silica aggregate and are highly plastic, so they're not easily used for filling large voids in a single application. However, they set quickly (in minutes) and successive applications to build up material thickness can be done right away. "Waterplug", made by the Thoroseal Corporation, is one of the better-known hydraulic cements that's typically used to plug water leaks in cracks and tie-bar holes in concrete foundation walls. It will probably work as well for your application.