Means for sealing expansion joints

Application filed. September 29,1926. Serial No. 138,457.

My invention relates to liquid containers, such as reservoirs for storing water, constructed of concrete slabs or any slabs of a material which contracts when lowered in temperature so that the joints between the slabs are caused to expand. .

Concrete reservoirs and like structures as heretofore macle have employed means for sealing the joints between the slabs of which the container is constructed, but such means is ineffective, to maintain a watertight seal for any length of time because the materials employed for filling the joints are porous, readily hardened, incapable of responding to expansion or contraction of the joints ancl are exposed to the deteriorating action of the water, air and sun. As a result, the percentage of failures in concrete storage reservoirs is high, especially so in reservoirs supported on earthen fills. In the building of reservoirs they are completed usually in the hottest months so that the concrete is expanded, making the joints between the slabs very narrow. It is at such times that the fillers are applied to the joints. Applying a roof and pumping water into the reservoir both effect a reduction in temperature of the concrete slabs, and hence a contraction of the slabs, resulting in widening of the joints. However, the greatest contraction occurs during the winter months of extremely low temperatures when the joints are expanded to such a degree as to render the fillers totally ineffective in sealing the joints. This temperature and resulting expansion problem also exists in fractures or cracks occurring in the slabs between the joints and under a head of water they increase in width. Disregarding contraction as a result of temperature, the expansion, of joints may be caused by failure to provide a hard and compact earthen sub-base, in which event the weight of water imposed on the slabs causes an uneven settlement of the sub-base resulting in a pulling apart of the slabs and thereby producing enlarged joints which destroy the usefulness of the fillers.

It is a purpose of my invention to provide a method of and means by which the joints between the slabs of a reservoir or the crevices occurring in the slabs can be inexpensively⁴ ancl permanently rendered watertight, irrespective of the expansive and contractive action of the slabs.

It is also a purpose of my invention, to provide a method of and means for sealing joints in reservoirs and the like in which the pressure or weight of the water contained in the reservoir is utilized to automatically maintain a water-tight seal at the joints. 60

I will describe only one method of and one means for sealing joints in reservoirs and like structures embodying my invention and will then point out the novel features in claims. ⁶⁵

In the accompanying drawings.

Figure 1. is a view showing in vertical section a portion of a concrete storage reservoir having applied to the joint occurring between two slabs thereof one means of seal- 70 ing the joint embodying my invention;

Figure 2 is a view similar to Figure 1 . showing the sealing means subjected to the weight or pressure of the water contained in the reservoir; . ⁷⁵

Figure 3 is a fragmentary sectional view of a concrete slab having a crevice therein to which is applied the joint sealing means embodying my invention.

Referring specifically to the drawings, my 80 invention, in its present embodiment, is shown applied to the joint 15 occurring between the confronting edges of two slabs 16 of concrete or other material, these slabs constituting a part of the bottom of a con- 85 Crete storage reservoir. Positioned beneath the slabs 16 and in spanning relation to the joint 15 is a concrete footing 17 which forms . a base upon which the adjacent edges of any two slabs are supported. 90

In carrying out my invention, I have filled the joint 15 with a compound relatively soft and non-hardening. This filler or compound may consist of various substances, such as hot poured asphalt or asbestos paste. 95 In the present instance, however, I employ' oakum, indicated at 18, which is. hammered clown into the bottom of the joint so. as to occupy about one-fourth of the joint. The oakum is then saturated with a suit- mo able preservative, such as elastic carbon black, which renders the oakum waterproof. The remainder of the joint is filled with a combination of elastic carbon black paint and long fiber asbestos, which, when mixed 105 together, preferably in equal parts, produce a putty-like substance 18^a which never hardens and remains soft and flexible.

With the joint filled as just described, the upper edge of the joint is now covered by the 110 application of one or more sheets or strips of suitable material, and which will be here2

1,691,402 inafter referred to as membranes. The membranes are designated at 19 and they may be constructed of burlap, cotton cord fabric, felt or any material that is soft and 5 pliable. In the present instance, I have shown a joint 15 provided with three membranes superimposed with respect to each other, and of graduated widths, the uppermost membrane being widest. These mem10 branes are. of sufficient width to extend beyond and to. opposite sides of the edges of the joint, as illustrated and they are secured in position by the use:of any gummy substance such as asphalt, pitch or the like, the 15 substance being hot when applied, and the membranes laid into this hot coat so that when it cools the membranes are securely held in proper positions. The substance employed is waterproof, so as to render the 20 membranes impervious to water and hence, prevent the passage of water into contact with the filling compound.

In practice, a joint sealed in accordance with my method renders the joint perma25 nently watertight, the membranes forming a protective covering for the filling compound so as to prevent water, air or the sun reaching and destroying the sealing property of the compound so that the latter is main30 tained in a soft and pliable state. With the introduction of water into the reservoir, the membranes are subjected to the pressure or weight of the water, and thus portions of the membranes spanning the joint 15 are flexed 35 downwardly as shown in Figure 2 to exert the desired pressure on the filling compound which causes the latter to expand and thus effectively seal any pores or crevices of the joint, thereby rendering it watertight. In 40 this manner, the filling compound is caused to completely fill and effectively seal the joint.should the latter expand under the contraction of the slabs.

Referring now to Figure 3 I have here 45 shown my method applied to the crevice 20 of a concrete slab for rendering it watertight. In this adaptation of my invention, the upper end of the crevice is cut out or enlarged transversely to form an elongated 50 groove 21 which is filled with tlie puttylike substance 18“, and then one or more membranes 19 are secured in covering and spanning relation to the crevice so that under a water load the membranes will be 55 flexed to cause the filling compound to expand in and effectively seal the crevice.

Although I have herein shown and described only one method and one means for sealing expansion joints.embodying my in60 vention, it is to be understood that various changes and modification may be made therein without departing from the spirit of the invention and the spirit and scope of. the, appended claims.