JP6571989B2 - Formulation of high standard fluidity improved soil - Google Patents

Description

  The present invention relates to a blending design method for high-standard fluidity improved soil in which an inorganic polymer is added to fresh concrete in a fresh state and mortar is adhered to the aggregate to granulate the aggregate.

Conventionally, the processing of the return concrete which became surplus in the concrete placement site, and the processing of the residue (sludge) generated with the cleaning of the manufacturing plant and the transport vehicle have been problems.
In particular, from the viewpoints of narrowing industrial waste disposal sites, rising disposal costs, and ensuring a stable supply of aggregates after the Great East Japan Earthquake, new high-value-added recycling of recycled concrete, which is industrial waste Technology is required.
Since there is no residue (sludge) mixed in the production of ready-mixed concrete, a method for production has not been established, and in the production method as a ground improvement material, cement-based solidified material is mixed with the target soil. However, although the mixing ratio with respect to the amount of the target soil is specified, there is a problem that the variation in the laboratory test and the field is large. In ground improvement, it is simply expressed by the addition rate of cement and lime to the soil volume.
In terms of the mix of concrete, it simply indicates the unit cement amount, but the unit water amount is not fixed. For this reason, hardening is inhibited by impurities such as moisture content of the soil, organic impurities (humic acid, tannic acid, etc.), mud and shells contained in the soil. Due to these factors, the determination of the optimum blend becomes trial and error, and stable strength management after improvement becomes difficult.

A processing method for improving the effective utilization of returned concrete is known (see Patent Document 1).
In this known technique, after adding a super retarder that prevents the setting of the returned concrete for at least 36 hours and, if necessary, a fluidizing agent that enhances the fluidity is added and mixed, the opening is 5 to 10 mm. This is a return concrete processing method in which a fine aggregate-containing mortar obtained by sieving using a sieve is used as a pre-feed mortar in a concrete pump method.

However, this well-known technique also does not fundamentally solve the processing of the return concrete surplus at the concrete placing site and the processing of residue (sludge) generated by the cleaning of the manufacturing plant and the transport vehicle. .
Therefore, in the present invention, a residue (sludge) derived from ready-mixed concrete is mixed using a method of granulating the aggregate by adding an inorganic polymer to the return concrete in a fresh state and attaching the mortar to the aggregate. “High-standard fluidity-improved soil”, which is a substitute for ready-mixed concrete, is manufactured, and “high-standard fluidity-improved soil” in which return concrete and residue (sludge) generate profits is converted to raw materials.

Japanese Patent No. 4344403

An object of the present invention is to provide a blended design method for high-standard fluidity improved soil in which an inorganic polymer is added to return concrete in a fresh state and mortar is adhered to the aggregate to granulate the aggregate. .

  The blending design method of the high standard fluidity improved soil of the present invention was granulated by adding a residue corresponding to a maximum of 25% of the volume of the return concrete, adding an inorganic polymer additive, and kneading the reference quantity. A process for producing IWA aggregate, a process for calculating quality characteristics of IWA fine aggregate and IWA coarse aggregate in the IWA aggregate, and a mixing ratio thereof, and a basic blending, a general concrete blending I. used in design The process of determining the water cement ratio from the target design standard strength using the “concrete strength to cement water ratio” relationship of the cement water theory proposed by Lyse, and for each water cement ratio used in the factory Based on the standard composition, the process of calculating the unit amount of each compounding material that satisfies the standard composition from the mixing ratio of IWA fine aggregate and IWA coarse aggregate of IWA aggregate, and the test kneading with the composition with different water cement ratio The method includes a step of determining a water cement ratio using a linear relational expression of a compressive strength and a cement water ratio, and a step of determining a blending ratio of each compounding material based on the water cement ratio.

The blending design method of the high standard fluidity improved soil of the present invention can be converted to a raw material from which return concrete and residue (sludge), which has been a long-standing problem in the ready-mixed concrete industry, generate profits, and have been suppressed. This can contribute to extending the life of the treatment plant, which has the effect of turning debt into assets in terms of management.
In addition, since this high standard fluidity improved soil can be provided at a lower cost than usual, it can be expected to reduce construction costs.

The blending design method of the high standard fluidity improving soil of the present invention will be described below.
Residue (sludge) equivalent to a maximum of 25% of the volume of the return concrete is added to the return concrete surplus at the concrete placement site, and an inorganic polymer additive ( for example, Re-Con Zero (manufactured by MAPEI); Name)) ), and then knead the standard quantity. The time is the reference time for the polymer additive. Using the granulated aggregate obtained in this way (hereinafter referred to as IWA aggregate), “high-standard fluidity improved soil” that is an alternative to ready-mixed concrete is manufactured.

  Next, the quality characteristics of the IWA fine aggregate and the IWA coarse aggregate in the IWA aggregate and the mixing ratio thereof are calculated (see Table 1).

The basic mix is more water than the target design standard strength using the “concrete strength to cement water ratio” relationship in the cement water theory proposed by I. Lyse, which is used in general concrete mix design. This is based on a method for determining the cement ratio.
According to this method, W (water), C (cement), S _IWA (IWA fine aggregates), G _IWA (IWA coarse aggregate) Each formulation material A _d (admixture), mix design of the concrete Since the blending calculation is performed including the volume of each blending material in the same manner as the method, strict blending design is possible (see Table 2).

The designated value of the normally used material in the ready- mix manufacturing factory (Noshiro Chuo-seikon Co., Ltd.) is obtained (see Table 3).

Quantity calculation using IWA aggregate based on aggregate quality characteristics (Table 1) and basic composition (Table 2) in the ready-mixed concrete manufacturing factory.

  Based on the above quantity calculation, an IWA aggregate usage recipe is created (see Table 4).

As a specific procedure, IWA aggregate IWA fine aggregate and IWA coarse aggregate mixing ratio based on the standard mix (Table 2) for each water cement ratio (W / C) used in the ready-mixed concrete manufacturing plant From the above, the unit amount of each compounding material that satisfies the standard compounding is calculated.
If there is no standard blending, use the standard blending table of the concrete standard specification (Japan Society of Civil Engineers), and the unit of each blending material that satisfies the standard blending from the mixing ratio of IWA fine aggregate and IWA coarse aggregate of IWA aggregate Calculate the amount.

Calculate the amount of coarse aggregate or fine aggregate that satisfies the standard composition by the ratio of coarse aggregate and fine aggregate in the IWA aggregate, and if one of them does not meet the standard composition, fill the shortage .
In this method, test kneading is conducted with different water cement ratios, the water cement ratio is determined using the primary relational expression of cement water ratio (reciprocal of water cement ratio) and compressive strength, and the factory has a standard blend In this case, the amount of IWA is determined from the formulation at the water cement ratio. When there is no standard blending, the concrete standard specification (JST) conducts test milling based on the rough values of unit coarse aggregate volume, fine aggregate ratio and unit water volume of concrete and a correction table to determine a predetermined blend.

[Examination]
The relationship between the strength of the concrete and the cement water ratio when adding fly ash at the time of IWA fine aggregate recovery and when adding it at the ready-mix manufacturing factory (Noshiro Chuo-seikon Co., Ltd.) is as follows. A similar relational expression between the strength of concrete and the cement water ratio can be established by test-kneading under the environment in each factory.
(1) Strength of concrete without adding fly ash to cement water ratio

(２)フライアッシュを添加した場合のコンクリートの強度〜セメント水比

(2) Strength of concrete when adding fly ash to cement water ratio

(３)ＩＷＡ骨材造粒時に残渣（スラッジ）を添加する場合のコンクリートの強度〜セメント水比

(3) Concrete strength to cement water ratio when residue (sludge) is added during IWA aggregate granulation

  I. used in general concrete mix design. The water cement ratio is determined from the target design standard strength by using the relational expression of “concrete strength to cement water ratio” in the cement water theory proposed by Lyse. This is a blending design method for “high-standard fluidity-improving soil” that has a process of confirming the strength and workability of concrete in advance by conducting test mixing with a composition determined based on this.

  As an additional note, the IWA aggregate test kneading record and the IWA aggregate test kneading result record at Noshiro Chuseikon Co., Ltd. are displayed (see Tables 5 and 6).

Claims (1)

Adding a residue corresponding to a maximum of 25% of the volume of the return concrete, adding a reference quantity of inorganic polymer additive, kneading and granulating the IWA aggregate, and adding to the IWA aggregate The quality characteristics of IWA fine aggregate and IWA coarse aggregate occupying, the process of calculating the mixing ratio, and the water cement ratio which is the basis of the blend design are used in the general concrete blend design. The process of determining the water cement ratio from the target design standard strength using the “concrete strength to cement water ratio” relationship of the cement water theory proposed by Lyse, and each water cement ratio used in the ready-mixed concrete manufacturing plant From the mixing ratio of IWA fine aggregate and IWA coarse aggregate of IWA aggregate based on the standard blending of IWA aggregate, the process of calculating the unit amount of each blending material that satisfies the standard blending, and the test kneading with a blend of different water cement ratio And determining a water cement ratio using a linear relational expression of concrete strength and cement water ratio, and determining a unit amount of each compounding material based on this water cement ratio. A concrete blending method for high standard fluidity improved soil.