RIGA TECHNICAL UNIVERSITY

BUILDING FACULTY

THE BUILDING MATERIALS LABORATORY

St. Azenes 16, Kipsala, Riga

Phone 708 9240; 708 9248; 9 404152 (mob.)

TESTING REVIEW Nr. 64-98

1. Boring of the samples

In June 18, 1998, from Riga city waste water mechanic and biological treatment station "Daugavgriva" there have been bored 3 concrete cylinders from each panel of 4^th block outer wall 10^~ panel and from inner wall 14^th panel in 1,5 m altitude. The diameter of bored cylinders 146 mm, height 150 ... 170 mm. These samples have been bored from the same panels, from what have been bored the samples for the examination in the October of 1996 (see the 1 st enclosure).

It has to be mentioned that the aerotank 4^~ block delimitation constructions - wall panels on surface had been treated with hydroinsulation material PENETRON.

2. Preparing of the samples and waterproofness verification

Bored cylinders had been sawed with diamond circular saw as to get the samples with height of 15 cm with sufficient smooth and perpendicular cut. Then the samples had been washed, dried at temperature +70 °C and cooled.

Waterproofness of the samples had been determined with the moist spot method in conformity with the State standard GOST 1273.5-84 requests. The scheme of verification equipment with the set samples are showed at 2^nd enclosure.

As the outer diameter of the cylinders was 146 mm, so it was not possible to put them correctly between the collapsible metal and rubber rings (by the data of passport the diameter of samples has to be 150 + lmm), because it was not possible to press the packing rubber rings tightly to concrete cylinder (in order to exclude later casual water leakage between the concrete sample and collapsible casing).

The standard allows to treat the concrete cylinders outer circumference surface with any material what excludes the later water leak through the cylinder sides, giving water under the pressure from the sample lower side. For insulation of the samples side surfaces there have been used the epoxide resin and fiberglass material in two plies.

Putting the cylinders in verification equipment, each sample has up and under the rubber pressure rings, what outer diameter was 19 cm, but inner - 12 cm. the plane rubber pressure rings covered the parallel ends of concrete cylinders over the samples circumference in 18 mm wide place (calculating from the concrete cylinders outer side). Under the upper rubber ring there have been placed the massive metal pressure ring, what has been attracted tightly with 4 bolts - in such way there have been averted the water filtration from the sample under by sample sides. The water had not filter through the concrete samples side surfaces, because the cylinders side surfaces had been treated with hydroinsulation materials. In such way the water, what have been given under the pressure from the cylinders lower side, could move up just through the concrete. After the tight fixation of samples under them from lower side with the pressure there have been given water, increasing the pressure by stages - with step 0,2 MPa. The pressure had been kept constant 16 hours to each stage. The obtained results (with the endured pressure showings) are summarized in Table #1 and Table #2.

Table #1

The results of waterproofness verification of concrete samples

Table #2

The comparising results of waterproofness verification of concrete samples

Chair of Building Materials.

Associate Professor, Dr. sc. ing. /Signature/ V. Zvejnieks

(Certificate Nr. ll06 issued by LBS "Physical verification and testing of building materials of buildings and edifices elements")

Director of laboratory, Ms. sc. ing. /Signature/G. Shahmenko

(Certificate Nr. 828 issued by LBS "Testing of building materials")

/Seal/

6 duly, 1998

Enclosure Nr. 1

Extract from "Examination conclusion of Riga city waste water mechanic and biological treatment station "Daugavgriva" aerotank 4^th block main delimitation ferroconcrete constructions technical condition" (agreement Nr. 6260/96, September - December, 1996)

Table #22

Waterproofness verification results

Note: These results have been obtained from samples in October, 1996.