Home＞Research and Technology Development＞Taiheiyo brand cement concrete＞Crack Control Tecnology : Measures

Taiheiyo brand cement concrete

Inquiries

		Ultra High Strength Technology				Crak Control Technology
＞Introduction		＞Background	＞Measures	＞Outlook		＞Background	＞Measures	＞Outlook

＞Introduction
Ultra High Strength Technology
＞Background
＞Measures
＞Outlook
Crak Control Technology
＞Background
＞Measures
＞Outlook

1Concrete Shrinkage Reduction Manual

The need for further drying shrinkage reduction technologies and techniques has been rising in order to produce higher levels of quality in concrete structures. In order to rapidly meet these needs, we have published a "Concrete Shrinkage Control Manual", a technical manual which contains information regarding material techniques and technologies used in shrinkage reduction. In addition to wide-ranging systematic experimental data using the products and materials the Taiheiyo Cement group offers, it also presents our own unique shrinkage prediction methods. We hope that it may serve of assistance in providing support to customers who are considering concrete shrinkage reduction techniques.

In addition to systematic experimental data, analysis is also performed based on the results of wide-ranging studies carried out by Taiheiyo Cement.

We performed performance evaluations on Taiheiyo Cement group company products used as shrinkage control technologies.

We studied the properties of aggregate, which have become a topic of interest due to their contributions to shrinkage. We also proposed prediction methods.

2Ready mixed concrete shrinkage variation study

We are working to improve quality for ready-mixed concrete factories. Many tests have been carried out in recent years to measure the amount of concrete drying shrinkage, but there has been almost no information regarding the amount of variation in the shrinkage of ready-mixed concrete actually produced in plants. We performed a year-round study to determine actual shrinkage conditions, analyzing variation factors to help create a system for supplying highly reliable concrete.

3Reduced shrinkage concrete

In order to respond to demand for reduced drying shrinkage ready-mixed concrete, we have worked with ready-mixed concrete plants to develop reduced shrinkage concrete (Minister of Land, Infrastructure, Transport and Tourism certified in September 2008). This technology combines limestone coarse aggregate, expansive additive (Hyper Expan), and shrinkage reducing agent (Tetraguard), products of the Taiheiyo Cement group. It has undergone extensive verification testing, confirming that it can be used to provide a stable supply of concrete with shrinkage as low as half of that of conventional concrete.

Equivalent to the special specifications in the Architectural Institute of Japan's "Reinforced Concrete Building Shrinkage and Cracking Reduction Design and Construction Guide (Draft) and Explanation".

In addition to length variation characteristics, we also confirmed that this concrete offers stable fresh concrete characteristics and compressive strength characteristics year-round.

4Quantification of cracking reduction effectiveness of various materials

A wide range of materials, such as low heat cement, expansive additives, and shrinkage reducing agents are used to prevent cracking. The effectiveness of those materials is recognized based on observation of cracking conditions in actual structures. However, the effectiveness of these materials must be quantitatively indicated in order to appropriately select which materials to use, and in what quantities, in order to rationally prevent or reduce cracking. We use unique testing and evaluation methods to quantitatively measure the crack reduction effectiveness of various materials.

We have experimentally assessed the effectiveness of materials such as expansive additives and shrinkage reducing agents at reducing cracking, as well as quantitatively evaluating their effects.