About reports such as falsification of cylindrical form strength test results from Kurimoto Iron Works Co., Ltd.

East Nippon Expressway Co., Ltd. ・Central Japan Expressway Co., Ltd. ・West Japan Expressway Used for construction of concrete hollow floor slab of Expressway managed and constructed by NEXCO3 Co., Ltd. Regarding the strength test of cylindrical formwork, Kurimoto Ironworks Co., Ltd. (Nishi-ku, Osaka City, hereinafter Kurimoto Ironworks Co., Ltd.), which is a manufacturer of cylindrical formwork, said, “Falsification of test data of cylindrical formwork, etc. was performed. I was told." It is very regrettable that the manufacturer has made such alterations to ensure quality.

The cylindrical formwork used for the concrete hollow slab bridge is not a structural member of the bridge body, but a temporary material until the concrete hardens. In addition, NEXCO3 does not have an immediate impact on safety because it checks the road surface of the bridge through daily inspections and performs detailed inspections of the bridge on a regular basis.

However, in response to this report, NEXCO3 will carry out an emergency inspection, and will promptly establish a committee of third-party academic experts to investigate and examine the construction quality and long-term impact.

NEXCO3 has just established "Cylinder type vacuum test method for floor slabs (JHS401)" and has confirmed the required deformation performance with respect to buoyancy generated during concrete placement during construction. This test measures the displacement by applying a load to the center of the span of a cylindrical formwork specimen with a span of 2 m.

Recently, Kurimoto Iron Works Co., Ltd. told NEXCO3 that "the test data was tampered with so that the load of this test was reduced and the amount of deformation was within the standard value" and "in the product catalog. There was a report that there was falsification regarding the plate thickness.

In addition to conducting an emergency inspection, a committee (chairperson: Shoji Ikeda, Professor Emeritus, Yokohama National University) of third-party academic experts was immediately established regarding the construction quality and long-term effects of the target concrete hollow slab bridge. Then, we will conduct an investigation.