ACL Project List
 

2013

 

Condition Assesment and Treatment Recommendations at Holly Tower Support Rock

Hovenweep National Monument

 

Laura Lacombe

 

Between 1985 and 2006, archaeologists at Hovenweep National Monument observed a dramatic increase in erosional loss on the west side of the Holly Tower support rock, which is a detached ledgerock of Dakota Sandstone. This thesis investigates the deterioration mode and pattern of the monolith, attributes cause to these observations, and proposes preventive and remedial treatments to stabilize the boulder based on existing research and historical precedent, as well as site survey and material testing. Delamination and excessive friability are addressed through physical and mechanical testing of a combined treatment program using Funcosil Antihygro, an anti-swelling agent, and Remmers KSE 300 E, an elastified ethyl silicate. Slab formation and large-scale loss are investigated for causal factors such as case hardening and frost cycling, and research in this thesis supports additional recommendations to test injection of consolidation treatment, pinning and grouting techniques to mitigate large-scale loss from slabbing.