I am using PROFIS to design the HILTI post-installed anchorage in a retrofit project. The project is based on ASCE 41.
I have the following questions regarding the installation conditions.
1) Per Environmental, Health & Safety (EHS) guidelines, it is recommended to use water to control dust when drilling anchor holes. For this condition, what hole type in PROFIS should I use? "Dry", "water-saturated concrete" or "water-filled hole"?
2) Is there any test or justification to determine how "dry" the hole needs to be to be able use the design values for "dry"?
3) I see that depending on the installation condition I use, the bond strength is modified based on the the tau, and Phi_bond values. Is there an ICC report or something were these values are referenced?
Thanks.
Hi Jorge,
1) Reviewing an adhesive anchor’s bond strength reduction factors, to understand the significance of their influence on the connection’s performance, may help when determining the hole type in PROFIS Engineering. However, this decision is heavily influenced by other factors, such as dust control in the given situation. The Hilti adhesive anchor selector chart can be found here as a quick reference for anchors and concrete conditions. The hole type determination for individual projects is at the discretion of the Engineer of Record.
2) ACI 355.4, Qualifications of Post-Installed Adhesive Anchors in Concrete, defines dry concrete as “concrete that, at the time of adhesive anchor installation, is 21 days and older and has not been exposed to water for the preceding 14 days.” Saturated concrete is further defined as “concrete that, at the time of adhesive anchor installation, has been exposed to water over a sufficient length of time to have the maximum possible amount of absorbed water into the concrete pore structure to a depth equal to the anchor embedment depth.”
3) Using ICC ESR-3814 for HIT-RE 500 V3 as an example, Table 11 provides bond strength design information that includes the tau and phi values. ICC-ES Reports for additional Hilti products can be found here.
Please feel free to reach out to hnatechnicalservices@hilti.com if there are additional questions.
Best,
Sam