Material(s) Selection / Design Criteria
It is our intent to develop a cost effective means of providing structural restoration for a variety of manhole structures. The following criteria determine the appropriate repair method for any specific manhole structure. Prior to the commencement of work, the project engineer determines condition and appropriate manhole repair method.
Manhole Condition Levels
Condition A
A manhole is considered fundamentally sound with indication of settlement, cracking or other signs of structural fatigue. The manhole may exhibit evidence of some non-structurally compromising degradation such as: missing brick and/or mortar joints, signs of infiltration or ex-filtration through pre-cast joints, mortar joints or around pipe connections. The existing manhole structure should be sufficient to sustain and support both soil and live loading.
Low to mild hydrogen sulfide environments (pH > 3.0). Substrate shall receive a minimum of ½” cementitious lining material manufactured from Type II Portland cement, and enhanced with silica fume. Materials shall contain poly-fiber reinforcement, chemical admixtures, and siliceous aggregates.
Approved material shall be Quadex QM-1s Restore as manufactured by Quadex, Inc.
Condition B
A manhole may exhibit any or all elements identified as Condition A. Further, the manhole is exhibiting early signs of structural fatigue evidenced by: minor cracks, loss of mortar or brick, evidence of mild to moderate biogenic sulfide corrosion attack. The rate (depth) of corrosion should be less than one-inch for every ten years of service life. The manhole may exhibit minor cross sectional distortion; however, the structure is still fully supporting the soil and live loads.
High hydrogen sulfide environments (pH > 2.0). Substrate shall receive a minimum of ½” cementitious lining material manufactured from 100% pure calcium aluminate cement and enhanced with high-density chemically stable aggregates. Materials shall contain poly fiber reinforcement and chemical admixtures.
Approved material shall be Quadex Aluminaliner as manufactured by Quadex, Inc.
Condition C
New construction with anticipated harsh hydrogen sulfide environments (pH < 2.0) or substrate corrosion < 0.125 inch and harsh hydrogen sulfide environments (pH < 2.0). Substrate shall receive a minimum of 125 mils of 100% solids epoxy lining material containing no VOC’s.
Approved epoxy material shall be Quadex Structure Guard.
Condition D
A Condition D manhole may exhibit any or all elements identified under Condition A and B. Further, the manhole may exhibit preliminary signs of severe structural fatigue and/or potential structural failure. Conditions indicating this degree of progressive structural deterioration are moderate to sever biogenic sulfide corrosive degradation great than one-inch in the mortar joints and pre-cast surface areas. The structure may exhibit loose and/or missing brick, exposed rebar or wire mesh reinforcement and/or distortion of the original manhole dimensions.
Severe hydrogen sulfide environments (pH < 2.0) and substrate corrosion > 0.125 inch. Substrate shall receive a composite system consisting of a minimum ½” cementitious lining material manufactured from 100% pure calcium aluminate cement and a 125 mil topcoat of 100% solids epoxy lining material containing no VOC’s.
Approved cementitious material shall be either Quadex Aluminaliner or Quadex QM-1s Restore and approved epoxy material shall be Quadex Structure Guard.
Note: The selected use of Quadex QM-1s Restore in Condition D composite system applications requires a minimum 7-day cure window prior to the application of the Quadex Structure Guard Epoxy.
Quadex Material(s) Selection Design Criteria 
