What does ASR look like in the field?

Generally, the first visual indication of an ASR affected structure is the development of cracks in the concrete structure. “Map” or “pattern” cracking is often seen in structures that are associated with ASR (although not exclusive), and are dependent on the severity of the attack, the type of structure affected, environmental and exposure conditions, restraint, and other factors. The direction of the cracking tends to be aligned in the direction of the main reinforcement.

Figure 1. Photo. Typical map cracking. This photo shows a close-up view of an ASR affected structure. Cracking is apparent in the entire photo, with some exudation in cracks, as wel as moisture stemming from the center of the cracks.
Figure 1. Typical map cracking.
Photo courtesy of Mr. Jon Mullarky

Figure 2. Photo. Map cracking in a section of pavement on Interstate 84 near Mountain Home, Idaho. This photo shows several longitudinal cracks along a concrete pavement section, with smaller cracks branching off transversely and diagonally.
Figure 2. Map cracking in a section of pavement on Interstate 84 near Mountain Home, Idaho.

Figure 3. Photo. Concrete barriers along Route 2 near Leominster, Massachusetts. This photo shows several horizontal cracks along two sections of concrete barriers, and the cracks are connected by several vertical cracks.

Figure 3. Concrete barriers along Route 2 near Leominster, Massachusetts.

Figure 4. Photo. A concrete girder treated for ASR in Corpus Christi, Texas. This photo shows several horizontal cracks along the face of a concrete girder, and the cracks are connected by several vertical cracks.
Figure 4. A concrete girder treated for ASR in Corpus Christi, Texas.

Figure 5. Photo. ASR affected column in Houston, Texas. This photo shows a close view of an ASR affected concrete column in Houston, Texas. Cracks are evident in the vertical direction, with popouts along the surface of the side of the column.
Figure 5. ASR affected column in Houston, Texas.

In severe cases, misalignment of concrete structures will occur due to the immense expansion caused by the distress upon the structure. In the case with pavements, this type of expansion could lead to joint failure or "heaving" of joint sealing material.

Figure 6. Photo. Misalignment of adjacent sections of a parapet wall on a highway bridge due to ASR-induced expansion. This figure shows the misalignment of adjacent sections of a parapet wall on a highway bridge. Although there is no scale, the lateral misalignment could be on the order of several centimeters. Both sections contain horizontal and vertical cracks.
Figure 6. Misalignment of adjacent sections of a parapet wall on a highway bridge due to ASR-induced expansion.