JPS5973461A - Concrete or mortar sludge composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sludge composition for concrete and mortar, which is intended for the effective use of sludge containing cement having water-use activity, for example, sludge contained in recovered water of a ready-mixed concrete factory. It is.

For example, in a ready-mixed concrete factory, the sludge contained in the collected water immediately after cleaning the plant mixer, transport vehicle, etc. contains cement that is in the process of being hydrated and unhydrated cement.

Therefore, the cement contained in these sludges still has the ability to activate water use, and the earlier the sludge is generated, the more active the ability to use water becomes. Therefore, if sludge containing cement that still has this water availability ability is used as part of the material for concrete or mortar to produce concrete or mortar, the cement contained in the sludge will be absorbed by the setting of the concrete or mortar. , hardening, etc., it can effectively perform its original function as a cement.

Based on this idea, sludge has often been used as a part of concrete materials. However, in most cases, conventional sludge is used for concrete only after the day after the sludge is generated due to various circumstances. For this reason, it takes a long time to elapse after the sludge is generated, and the cement contained in the sludge loses most of its water use activation ability as water use progresses. The reality is that it is not possible.

The present invention has been made in view of the above circumstances, and its purpose is to stably maintain the water utilization ability of sludge containing cement having hydration activation ability for a long time, and to make the sludge into concrete. Or, it is intended to be used most effectively as a material for mortar.

The inventors conducted extensive research and investigation into how to maintain the water-use activity of the cement contained in sludge stably for a long period of time.As a result, the inventors created a slurry by concentrating the sludge by precipitation separation or other means. By adding an appropriate amount of setting retardant to this condition, it is possible to suppress the progress of hydration of the cement contained in the sludge and maintain its water use activity for a long time.As a result, the sludge They discovered that it could be effectively used as a material for concrete or mortar, and completed this invention.

That is, the present invention provides a sludge composition for concrete or mortar, which is obtained by adding a setting retarder to sludge containing a cement component having water-use activity.

In the present invention, the amount of the setting retarder added to the sludge is
It should be determined according to the cement content in the sludge, the use of concrete or mortar, the expected storage period of the sludge, etc., and cannot be unconditionally defined, but it is usually 0.4% relative to the cement content in the sludge. ~0.8 wt% is added. The timing of adding the setting retarder to the sludge is preferably within 4 hours from the generation of the sludge, and the earlier the addition, the more effectively the progress of water utilization of cement can be suppressed. Examples of setting retarders include commercially available ones such as Litar (trade name, manufactured by Onoda Kenzai Co., Ltd.), Sevian SS (trade name, manufactured by Eiri Kagaku Kogyo Co., Ltd.), Balik T (trade name, manufactured by Fujisawa Pharmaceutical Co., Ltd.), and others that have a setting retarding effect. There are no particular limitations as long as the desired admixture is used.

Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

The cement used was ordinary Portland cement, and its properties were as follows.

Example 1 1 part by weight of ordinary Portland cement and 15 parts by weight of tap water
Water-cement ratio (W/C) 1 made by weight part as material
The 500% sludge water was thoroughly stirred and separated by precipitation, and the supernatant water was discarded to obtain a sludge in a slurry state. Two hours after water was added to this sludge for sludge trial production, Balik T (trade name manufactured by Fujisawa Pharmaceutical Co., Ltd.) was added as a setting retarder to α4% of the solid content of the sludge.
wt% was added and mixed thoroughly. After 1 day and 3 days have elapsed after the addition of the retarder, the retarder-added sludge was mixed to a level where the sludge solid content was 15% of that of the cement.
Regarding the substitute for cement 1 to be a substitute for
Set and strength tests were conducted. The amount of water used in the test was calculated by taking into account the sludge moisture content and subtracting the corresponding amount. Table 1 shows a comparison of the test results conducted on cement (standard cement) that does not substitute sludge.

Example 2 Using sludge obtained in the same manner as in Example 1, 4 hours after adding water to a sludge trial tank, Balik T (trade name manufactured by Fujisawa Pharmaceutical Co., Ltd.) was added as a setting retarder to the sludge solid content. Setting and strength tests were carried out in exactly the same manner as in Example 1, except that 0.8 wt % was added.

Table 2 shows a comparison with the test results conducted on cement that does not replace sludge (standard cement).

Table 2 Comparative Example 1 Sludge obtained in the same manner as in Example 1 without adding a setting retarder was added to cement at 15% after one day.
Instead, the same test as in Example 1 was conducted. Table 3 shows a comparison with the test results conducted on cement that does not replace sludge (standard cement).

Table 3 Comparative Example 2 Using sludge obtained in the same manner as in Example 1, 8 hours after adding water for sludge trial production, Pariku T (trade name manufactured by Fujisawa Pharmaceutical Co., Ltd.) was added as a setting retarder. The same test as in Example 1 was conducted by adding α8 wt % to the solid content of the sludge, and after one day had passed, 15 g of this was substituted for cement.

Table 4 shows a comparison with the test results conducted on cement that does not replace sludge (standard cement).

As is clear from the test results described in Example 1.2 and Comparative Example 1.2 of Table 4, by adding a setting retarder to the sludge at an early stage as in the present invention, some of the cement varnish sludge can be Even if the sludge is replaced, the setting and strength are almost unchanged compared to cement that is not replaced with sludge, indicating that the cement contained in the sludge still has the ability to activate water use. On the other hand, when cement is substituted for sludge without adding a setting retarder and sludge to which a setting retarder is added after 8 hours has elapsed after water is added, the setting time increases.

It is clear that strength has negative effects that cannot be ignored.

As described above, according to the present invention, sludge can be used without deteriorating the quality of concrete or mortar, and the sludge can be stored for a long period of time. It can be effectively used as

Patent applicant: Toyo Soda Kogyo Co., Ltd. Patent applicant: Toyo Koun Co., Ltd.

Claims (1)

[Claims] A sludge composition for concrete or mortar, which is obtained by adding a setting retarder to sludge containing a cement component having water-use activity.