FUKO Injection System", which is distributed by the company. ... proofing action of
the FUKO Injection System should be judged by means of test specimens and ...
Expert Opinion G 10/90 Function principle and sealing action of the FUKO Injection System from laboratory testing
Page 2 to Expert Opinion G 10/90 from 26th. October 1990 1. General Information For the United States Office: Absolute Waterproofing Systems inc. 200 Railroad Avenue Greenwich, Connecticut 06830
commissioned me with letter Ko-re from 9 March 1990 with the assessment of the FUKO Injection System", which is distributed by the company. This assessment should be made from the results of laboratory testings. The testing program and the accompanying test specimens were laid down during a conversation on 15 February 1990. The following men were present at the appointment: Mr. Koob, Managing Director BBZ Mr. Meyer, Managing Director BBZ Mr. Dr. Vinkeloe, advisory to BBZ Mr. Prof. Neisecke, Expert. Those taking part in the discussion agreed that the function principle and the waterproofing action of the FUKO Injection System should be judged by means of test specimens and laboratory testings, which should be done under conditions as near to real life as is practicable.
2. The FUKO Injection System The FUKO Injection System consists of three major components: - injection hose - injection material - injection tool (pump). The essential part of the system is the FUKO Injection Hose, which - depending on the injection material - can be supplied in two diameters. Its lateral openings for the injection material are secured by closed-pore neoprene strips from the outside against the penetration (plugging) of cement paste from the concreting process. When put under pressure from the inside the neoprene strips are compressed and release the injection openings even if the hose is completely coated with concrete. This action is an indispensable prerequisite for not only cavities but also crack areas or construction joints can be injected, as long as they are linked to the hose.
Page 3 to Expert Opinion G 10/90 from 26th. October 1990 Enclosure 1 is used for explanation of the structure and function of the FUKO Injection Hose. Detailed specifications on the FUKO Injection System may be obtained from the company brochure. The above and the following specifications are based on the paper "FUKO Injection System" by BBZ. Cement and polymer bounded, low viscosity materials are available for injection, which can be processed by means of injection tools (pumps) with pressures up to 50 bar (711.14 psi). BBZ names the following major range of application: - Injection of vertical and horizontal construction joints including connected structural distortions (honey-combs, cracks). - Injection of cracks at dummy joints. - Additional securing of joint tapes against leakage. - Additional securing of other critical areas during sealing of concrete buildings.
3. Examination Program and Implementation 3.1 Examination Aim «
The task of the examination was to settle the following questions: - Is it possible to caulk construction joints with the FUKO Injection System? - Can structure distortions - like for example honey-combs - be in injected, even if they are not passed through by the injection hose, but are only connected with it by the construction joint? - Are crack areas, which cross the injection hose, covered by the injection material? - Is it possible to safely take the injection material out of the hose immediately after the injection process, in order to enable a reinjection, which might be necessary later on? Naturally beside these central questions all other actions and results should be recorded, as long as they might be important for the practical application of the system or a possible subsequent examination.
Page 4 to Expert Opinion G 10/90 from 26th. October 1990 The preparation of the test specimens, as well as the later injection, forcing off and cutting was completed on the company grounds of BBZ in Willich, because all required equipment and necessary engineering staff was available throughout the testing time period. Supplementary examinations on small test specimens, like for example the waterproofing-test according to DIN 1048, took place at Dortmund University. The expert was present for all steps of the work and also examination. A colleague stood in, who wrote a report and took documentary photographs. The injection, the water pressure test, and the cutting of all the test specimens, took place in the presence of the expert.
3.2. Test Specimens Altogether 6 test specimens (amongst these no. 3 was kept in reserve) of the measurements, 200 cm x 50 cm x 20 cm were prepared out of concrete approx. highdensity-concrete B 35, normal Portland cement PZ 35 F, water-cement ratio = 0.5. These specimens each consisted of a 10 cm thick bottom slab, on top of which an also 10 cm thick top slab was concreted. In order to create a construction joint between the top and the bottom slab - a hydrophobic sealing medium was added to the lower concrete - the lower concrete was thoroughly watered prior to placing the upper concrete to achieve a distortion of the bond. To prevent a rise or shearing off of the upper concrete from the bottom slab during a later injection, caused by pressure built up in the construction joint, a lateral tie reinforcement was built in between the bottom and the top slab. After curing of the lower concrete an injection hose was nailed onto each of the first 4 specimens parallel to the specimens' longitudinal axis, but off centre (lateral distance 30 or 20 cm). Additionally, two honey-combs were created at a time by making up gravel of 2/8 mm grain. One of the honey-combs contained the injection hose, while the other was placed 5 - 8 cm next to the hose. On the other hand in the cases of specimen 5 and 6 the injection hose is centered with a lateral distance of 25 cm. Here honey-combs were not made up, because bending cracks could be created at these specimens by a single overloading later on. These cracks then were 1 mm wide at the top side of the slabs. The bottom of the slab did not show any cracks. Details and measurements of the specimens can be taken from image 2 to 4 of the enclosure.
Page 5 to Expert Opinion G 10/90 from 26th. October 1990 3.3 Injection Material As injection material were used: - Polyurethane injection resin IH-88 (components A and B), almost colourless (manufacturer: BBZ Building Chemistry). - Duroseal Inject R-581 (based on Vinylester from root component A and activating component B), intensive yellow, but can also be changed to red or orange by inking (manufacturer: BBZ Building Chemistry). - Injection Cement Z 1, cement grey (ultra fine cement as powder component A plus a liquid addition agent as component B). Duroseal and the Injection Cement are "water-soluble" when still uncured, so that emptied hoses and tools can be cleaned by rinsing and thus are available for reinjections, if this becomes necessary. According to manufacturer's specifications Duroseal expands by the factor 1.6 which is of great importance for sealing cracks and joints. This swelling is said to be almost completely reversible after drying out.
3.4 Test Specimens Injection The injection process at the test specimens was based on the following pattern: Step 1 (injection) Injection of the injection material, after the injection hose was filled and then closed at its delivery end. With an injection pressure of 10 bar (142.22 psi) the injection lasted for approximately 3-10 minutes. The process was stopped, when a larger amount of injection material emerged from the sides of test specimens from single construction joint areas. Usually a reinjection was carried out from the other end of the hose at once, until lateral emergence was observed again. Step 2 (System Cleaning) Immediately after the injection the hose was cleaned from the injection material (extraction of the injection material from the injection hose of the specimens by means of a vacuum system, rinsing until the rinsing water is clear, short blowing through with compressed air). The hose was now available for reinjection. This step, however, is only possible with the uncured water-soluble injection materials: Injection Cement Z 1 and Duroseal Inject R-581.
Page 6 to Expert Opinion G 10/90 from 26th. October 1990 Step 3 (1. reinjection). Approximately 2 hours after the first injection (step 1) the same procedure as in step 1 is used again. The manufacturer assumes that the injection material/that in the meantime has started to harden in the test specimens seals off leaks, through which a larger amount of injection material had emerged. So with fresh injection material of this first reinjection additional areas can be injected, which were not reached because of leakages during the first injection. This first reinjection was carried out through the cleaned hose using Duroseal, by reinjecting fresh resin into the filled system using polyurethane. In case of cement injection Z 1 this step is dropped, because the material was not sufficiently stiffened after 2 hours. A reinjection of Duroseal and Cement Inject is always possible with cleaned hoses and after sufficient hardening. Hoses filled with polyurethane can only be reinjected within the potlife, because a cleaning is not possible at present. Step 4 (System Cleaning) Process analogous to step 2. Step 5 (2. reinjection) After 2 days same process as under step 1 or 2, however with higher pressures of up to 50 bar (711.14 psi) this time. This step can only be carried out on test specimens with cleaned injection hoses. Step 6 (System Cleaning) Like step 2 and 4. According to this pattern test specimens 1, 2, 4^5 and 6 were injected in the following manner: Test specimen 1 (construction joint, honey-combs) compare images 2, 3 and 5 - Injection (polyurethane) - 1. reinjection (polyurethane). Test specimen 2 (construction joint, honey-combs), compare images 2,3 and 6 - Injection (Duroseal yellow) - Cleaning - 1. reinjection (Duroseal pink) - Cleaning - 2. reinjection (Duroseal red) - Cleaning.
Page 7 to Expert Opinion G 10/90 from 26th. October 1990 Test specimen 4 (construction joint, honey-combs), compare images 2, 3,7 and 8 - Injection (Inject Cement) - Cleaning - 2. reinjection (Duroseal red) - Cleaning (On these test specimens injections were carried out according to work step 5 (2. reinjection). Test specimen 5 (construction joint, bending crack), compare images 2, 4 and 9 - Injection (Duroseal yellow) - Cleaning - 1. reinjection (Duroseal pink) - Cleaning - 2. reinjection (Duroseal red) - Cleaning. s•
Test specimen 6 (construction joint, bending crack), compare images 2, 4 and 10 - Injection (polyurethane). 3.5 Water pressure checking for compactness by means of injection hose In principle, cleaned injection hoses provides the opportunity to check the success of sealing by means of the injection hose. Therefore, the injection hoses of test specimens 2 and 4 (construction joint, honey-combs) as well as of test specimens 5 (construction joint, bending crack) were filled with water. The water pressure was then increased to 3.50 bar (49.78 psi). This load was effective for three days and lead to the following results: - Test specimen 2 (construction joint, honey-combs, Duroseal). No water emergence at the lateral construction joints. - Test specimen 4 (construction joint, honey-combs. Inject Cement + Duroseal). Water emergence in the area of the construction joint at the one front end of the test specimen. It was suspected, that because of the water pressure, the swelling Duroseal drew the test specimen apart from the lateral tie reinforcement along the construction joint. Because such a joint movement is not possible in real life applications, this test specimen was reinforced by means of pusher beams against the laboratory sealing. The water flow then stopped after 10 minutes, which could explain by the reswelling of Duroseal in the now hard and fast joint. - Test specimen 5 (construction joint, bending crack, Duroseal). No water emergence at the construction joint or the bending crack.
Page 8 to Expert Opinion G 10/90 from 26th. October 1990 3.6 Cutting of the test specimens For an optical assessment of the injection results all test specimens were cut according to the enclosed cutting plan (compare image 11) by means of a diamond wheel. The cuts S 1 - S 6 were made, so that construction joints as well as all honey-combs and bending cracks could be assessed. The visual assessment of the area of the cut gave the following results: - The injection materials Injection Resin iH-88 (polyurethane), Duroseal Inject R-581 as well as Inject Cement Z 1 emerge out of the hose into the construction joints with a width in an order of magnitude > 0.1 mm (compare images 12, 14 and 16). - In all cases honey-combs could be filled with the above named injection materials, if they were only linked to the 5 - 8 cm distant injection hoses thorough the approximately 0.1 mm wide construction joint (compare images 12 and 14). The honeycombs, which were directly passed through by the injection hoses, were injected (compare images 13, 15 and 17). Small air bubbles with a diameter of 1 - 2 mm were found scattered in injected with Injection Resin IH-88 (polyurethane [compare images 12 and 13]). - The bending cracks of test specimens 5 and 6 were injected (which was not surprising considering their crack width) at the junction with the hose of more than 0.22 m. The cracks widened towards the top to approximately 1 mm (compare images 19 and 20). - Pores or smaller injection deficiencies were found close to the injection hoses, which were obviously reached by the injected substance through a porous concrete structure. These, too, were then filled. From the red color of the Duroseal, which was detected in that area, it can be expected that this additional cavity filling can only be achieved with the high pressures of the 2. reinjection (compare image 18). - During the splitting of the test specimens along the longitudinal axis, areas were found where no injection good was discovered. Actions like this surely occur, when the injection pressure falls due to leakages to such a low level that an all-over injection of the complete construction joint is no longer possible. However, it seems, first and foremost, to be of decisive importance that along the complete injection hose a continuous strip is tightly injected into the construction joint.
Page 9 to Expert Opinion G 10/90 from 26th. October 1990 3.7 Supplementary examinations on water impermeability Because a water loading on the side of the construction joint it was not possible to technically examine the impermeability of test specimens 1-6. An attempt was made to carry out such kind of examination on cut out specimens. The specimens were cut to the dimensions 20 cm x 20 cm x 12 cm, so that they could be built into the apparatus for water impermeability testing of concrete according to DIN 1048 (compare image 21). Parts of the cut specimens could not be tested, because they did not stay together due to missing lateral tie reinforcements and broke up along the construction joints or along the cracks. However, it was possible to tie together three specimens, which were injected with Duroseal, by means of a metal framework, which prevented a widening of the construction joint - even in the case of Duroseal which swells as a result of water loading. These specimens did not allow water to pass through during water loading according to DIN 1048 in steps, of 1 bar (14.22 psi), 3 bar (42.67 psi) and 7 bar (99.56 psi). With one specimen a dull humidification was discovered along the joint (compare image 22 and 23). In this case the large swelling action of Duroseal definitely proofed to be advantageous. 4. Conclusion and Recommendation The above described examinations on laboratory test specimens with the FUKO Injection System lead to the following results: 4.1 The used injection technique made it possible to inject the injection materials - Injection Resin IH-88 (polyurethane) - Duroseal Inject R-581 - Injection Cement Z 1 through the FUKO Injection Hose into construction joints in ah order of magnitude ^0.1 mm width. 4.2 It was possible to fill larger honey-combs through such kind of construction joints. The honey-combs had a lateral distance of 5 - 8 cm from the injection hose. Honeycombs which were passed through by the injection hose were also injected. 4.3 The injection good penetrates into crack areas, which cross the injection hose. 4.4 The cleaning of the FUKO-injection hose by vacuum emptying and water rinsing certainly succeeds with the injection materials: Inject Cement Z 1 and Duroseal Inject R-581. Thereby a reinjection becomes possible any time and as often as one likes.
Page 10 to Expert Opinion G 10/90 from 26th. October 1990 4.5 By reinjecting with pressures of up to 50 bar (711.14 psi), areas which before were not injected, - (even small pores and structural imperfections in areas close to the hose) - could be filled, through the cleaned injection hoses. 4.6 One has to assume that construction joints are not reached evenly across the full area by the injection material during injection. However, there is no evidence, which refutes the fact that in all test specimens a continuous strip was tightly injected parallel to the injection hose and in all the surrounding areas. Naturally, one can not overlook the fact that the conclusions presented in 4.1 - 4.6 were reached with only 2 m long and 20 cm high laboratory test specimens. However, if one takes into account that the examination was first of all intended to assess the functional principles and the sealing action of the FUKO Injection Hose, then the conclusions are highly convincing. In addition, during the assessment the expert was able to see for himself, the simple and safe laying of the injection hoses as well as the functioning of the injection technique under construction site conditions on a large-scale building site in Dusseldorf, Germany, in June 1990. (Prof. Dr.-Ing. J. Neisecke)
Picture 3 Preparing of the test specimens 1-4
Picture 4 Preparing of the test specimens 5 and 6
