TEHRAN -- An expert recently criticized the inept restoration work done on the Khaju Bridge, one of the most famous historical structures built over the Zayanderud River in Isfahan.

Workers used cement for restoring the historical bridge, but Omid Udbashi believes that they should have used another type of mortar instead of cement, the Persian service of the Mehr News Agency reported on Sunday.
Restoration work was completed by experts from the Isfahan Cultural Heritage, Tourism and Handicrafts Department (ICHTHD) last summer.
Cement causes corrosion of stones used in the construction of the bridge, he added.
“Due to the lime content of the stones, other types of mortar should be used in this kind of a restoration project,” he stated.
He noted that using cement in the restoration of monuments was done away with over 40 years ago.
According to Udbashi, the cement mortar has been eroded away by the river passing under the bridge.
He said that a monument needs to be studied carefully before undertaking any restoration work on it. However, such research is usually omitted in Iran due to the high cost of such studies.
In August 2009, the Isfahan Press Activists Society issued a statement to censure the inept restoration on Khaju.
Over 40 journalists who signed the statement said that the restoration had ruined the authenticity of the Khaju Bridge.
The bridge is also being threatened by the growth of grass and algae in the gaps between the stones used in construction of the monument.
The Khaju Bridge was built around 1650 during the reign of the Safavid king Shah Abbas II on the foundation of an earlier bridge.
Comprised of 23 arches, the bridge is 105 meters in length and 14 meters in width.
The Khaju Bridge had previously been restored in 1873.
In November 2009, Si-o-Se Pol, another historical bridge built over the Zayanderud River in Isfahan, was damaged by a tunnel boring project for the Isfahan Metro.
The tunnel-boring machine deviated from its intended route and bumped into a ramp and a lower part of the bridge.
Si-o-se Pol, also known as the Allahverdi Khan Bridge, is one of a small number of Isfahan’s historical bridges spanning the Zayanderud.
The construction of the bridge began in 1602 by order of the Safavid king Shah Abbas I.
Photo: The photo shows that mortar used to fill the gaps between the stones in a part of the Khaju Bridge has been removed by the flowing water of the Zayanderud River less than one year after restoration. (Photo by Mehr)