Research Trends and Results

Outer wall diagnosis technology for long life use of thebuilding
MAKATAYAMA Miho, HeadHousing Department, Housing Stock Division
TANANO Hiroyuki, Research Coordinator for Quality Control of Building
Building Department
NEMOTO Kaori, Senior researcher
Structure Standards Division（Key words）

Outer wall diagnosis, Control and maintenance, Periodical report institution

1. Introduction
Appropriate control and maintenance are required tomaintain the building outer wall in a good condition andthere is a risk that the outer wall drops and results in aserious accident to cause injury on the third party if you
failed to keep periodical check and diagnosis.
Revision on the periodical report institution of theBuilding Standards Act chapter 12 has obliged us to carryout the outer wall research through the overall soundingon the specific building that has passed 10 years fromfinal completion or large degree reconstruction sinceApril 2008. However, practice of the research diagnosis
remains low percentage as it is required to prepare afoothold to implement the outer wall research through theoverall sounding and it costs high. Although infrared ray
diagnosis is utilized as the diagnosis method without
foothold, but what is ongoing is the combination use withthe overall sounding as the climate and location
conditions might make the infrared ray diagnosis difficult
to practice.
Based on such a situation, we have started to develop
the outer wall diagnosis method that is simple andreliable and further possible to have qualitative evaluationand proceeded on the study on how to practice the outerwall diagnosis and what to consider its result on trying
experimental verification.
2. Developing the outer wall diagnosis system anddiagnosis guideline
We have made a prototype of the “Wall face runningouter wall diagnosis system” that self-runs on the wall
face and implements the sounding diagnosis in a given
place in order to realize the outer wall research in a placedifficult to approach for the inspector such as on highplace outer wall. (Refer to the figure.) The prototype has
perpendicular three legs and runs on the wall face
stepping the upper and lower two legs and central one leg
alternatively. Diagnosis to detect loosen tile and the likeis implemented based on the sounding method.
Furthermore, there is a problem of variation on thediagnosis depending on the skill and experience of theinspector in the sounding inspection that is a basis of theactual outer wall diagnosis. Therefore we have developed
the “Manual outer wall diagnosis system” that enables thequalitative evaluation and makes it possible to leave thedata of the diagnosis result. We were supposed to haveused it in a same manner of using the sounding stick inthe sounding inspection and made a specification that canbe used in a daily check.

a. Diagonally looked viewb Looked from upwardIn
this research, adding to the development of theFig. Wall running type outer wall diagnosis system prototype
system and method, we have also made the guideline of
The outer wall diagnosis investigation and filed thetechnology material. In particular, on the reconstructed
and/or repaired wall, it is difficult to judge whether
deterioration such as loosen parts is increased or not
different from the wall before reconstruction. To refine
the guideline, we have verified the applicable range of thesounding method and infrared ray method including thereconstructed wall in the study objective and studied onthe alternative investigation method and historical data on
the reconstruction work required for the control andmaintenance. Those results were used for the guideline ofthe practical method, evaluation and judgment of theouter wall diagnosis.
3. Future planning
We are to make the public announcement of theperformance and specification of developed wall facerunning outer wall diagnosis system and do filing of theouter wall diagnosis guideline (Plan) and technology
material with the objective of reconstructed wall and start
to finalize and control the technology so that the outerwall diagnosis is ensured to put to practice.