31results about How to "Overcome the disadvantage of low strength" patented technology

The invention discloses a preparation method of high-strength fully-recycled coarse aggregate concrete, belonging to the technical field of recycled coarse aggregate concrete. According to the preparation method, a proper amount of superplasticizer, first-level coal ash and mineral powder are added at a water-gel ratio of 0.36-0.44 to prepare the high-performance fully-recycled coarse aggregate concrete which is good in working property, high in early-stage strength and good in later-stage strength development. The strength of the existing fully-recycled coarse aggregate concrete is low, and the compression strength of the fully-recycled coarse aggregate concrete provided by the invention is over 50Mpa according to actual measurement in 28 days.

The invention relates to a splicing-type primary support method for a tunnel. Therefore, constructions in special sections of weak geological conditions can be effectively supported when a shield method for construction is not adopted for tunnels excavated by a mining method and primary support of underground construction. The splicing-type primary support method comprises an overall support and partial excavation support and is characterized in that based on a tunnel section form, a support member is divided into multiple blocks; on the site, the multiple blocks are attached to the excavation surface for splicing into a ring so that surrounding rock deformation is controlled; in the method of partial excavation support, rings are formed by partial excavation so that overall connection is formed. The surrounding rocks are supported timely and deformation is controlled. The working environment is improved. The primary support time is shortened and safety coefficients of the working surface construction are improved. Stress is more uniform. The construction quality of a water-proof layer is ensured. Mechanical installation is achieved and high efficiency is obtained. The splicing-type primary support method is used more flexible and has a broad application scope. The support cost is low.

The invention relates to a nanostructured pure titanium plate preparation method which includes the following phases: (1) selection of titanium powder particles, to be more specific, low oxygen and low hydrogen high purity titanium powder particles are selected, and the titanium powder particle size distribution range is 5-200 microns; (2) preparation of a pure titanium plate blank by high speed spray deposition method, to be more specific, titanium powder particles are accelerated, by collision of the high speed titanium powder particles and a substrate, a pure titanium plate blank is prepared by deposition caused by strong plastic deformation of the titanium powder particles; (3) plate blank heat treatment, to be more specific, and heat treatment of the prepared pure titanium plate blank is performed; and (4) hot rolling. The crystalline grain size of the pure titanium plate prepared by the method is small, the crystalline grain is nanocrystalline, uniform in organization, and excellent in performance, the shortcoming of low strength of the pure titanium plate is overcome, the hardness is 2 times greater than that of ordinary pure titanium plates, at the same time, the advantages of excellent corrosion resistance, heat resistance and biocompatibility and the like of the ordinary pure titanium plates are inherited. The nanostructured pure titanium plate preparation method is simple in process, good in controllability, and high in production efficiency, and helps to industrial application.