A concrete mixer (often colloquially called a cement mixer) is a device that homogeneously combines cement, aggregate such as sand or gravel, and water to form concrete. A typical concrete mixer uses a revolving drum to mix the components. For smaller volume works, portable concrete mixers are often used so that the concrete can be made at the construction site, giving the workers ample time to use the concrete before it hardens. An alternative to a machine is mixing concrete by hand. This is usually done in a wheelbarrow. According to the working nature, it can be divided into batch type (batch type) and continuous type; according to the stirring principle, it can be divided into self-falling type and forced type; according to the installation method, it can be divided into fixed type and mobile type; According to the structure of the mixing drum, it is divided into pear type, drum type, double cone, disc vertical shaft type and circular groove horizontal shaft type.
A mixing paddle is a shaped device, typically mounted on a shaft, which can be inserted on the shaft end into a motorised drive, for the purpose of mixing liquids, solids or both. Paddle mixers may also be used for kneading. Whilst mounted in fixed blending equipment, the paddle may also be referred to as an agitator. Mixing paddles are used for mixing ingredients in cooking and for mixing construction products, such as pastes, slurries or paints. They are also used for dispersing solids within liquids (for example, some polymers may be delivered in solid form, but will dissolve in liquids). It has the following characteristics: 1. The anchor type and frame type are generally used at low speed between 60 and 300rpm. This is because considering the length of the anchor type and frame type is 3 to 5 meters, the support point is located at the shaft head, and the stirring shaft is The strength is limited, and the stirring shaft beats relatively large at high speed, especially the shaking at the bottom of the stirring range is large, and even touches the inner wall of the reaction kettle. At the same time, the number of revolutions is selected in combination with the viscosity of the material. The viscosity is large and the speed is low, and the viscosity is small and the number of revolutions is an appropriate high point; 2. Turbine type: There are many blades, many types, and high speed, so that the fluid can be changed from vertical movement to horizontal movement evenly; 3. Propulsion type: The propulsion type is also called the propeller type. It is often cast as a whole. When welding is used, it is difficult to process the shaft sleeve after die forging. The static balance experiment should be done during manufacture, and the shaft can be connected with the shaft sleeve, flat key and set screw.
A concrete grinder can come in many configurations, the most common being a hand-held angle grinder, but it may be a specialized tool for countertops or worktops. Angle grinders are small and mobile, and allow one to work on harder to reach areas and perform more precise work. There are also purpose-built floor grinders that are used for grinding and polishing marble, granite and concrete. Machines that grind concrete floors are usually made to handle much more stress and will have more power to drive the unit as concrete has a much higher sliding friction than marble or granite which is also worked wet, therefore with less friction. In fact some types of marble will spark when it is ground dry, causing deep damage to the marble surface. Floor grinders are most suitable to polishing a concrete floor slab as it can cover large surfaces more quickly, and they have more weight on them, therefore making the actual grinding process more efficient. All concrete grinders use some sort of abrasive to grind or polish such as diamond tools or silicon carbide. The diamond tools used for grinding most commonly are diamond grinding cup wheels, other machines may use diamond segments, mounted on varies plates, slide on diamond grinding shoes and for polishing are usually circular Resin diamond polishing pads. The use of diamond attachments is the most common type of abrasive used under concrete grinders and come in many grits that range from 6 grit to the high thousands, although 1800 grit is considered by the insurance industry as the highest shine to apply to a floor surface.
A screwdriver is a tool, manual or powered, used for driving screws. A typical simple screwdriver has a handle and a shaft, ending in a tip the user puts into the screw head before turning the handle. This form of the screwdriver has been replaced in many workplaces and homes with a more modern and versatile tool, a power drill, as they are quicker, easier, and can also drill holes. The shaft is usually made of tough steel to resist bending or twisting. The tip may be hardened to resist wear, treated with a dark tip coating for improved visual contrast between tip and screw—or ridged or treated for additional 'grip'. Handles are typically wood, metal, or plastic and usually hexagonal, square, or oval in cross-section to improve grip and prevent the tool from rolling when set down. Some manual screwdrivers have interchangeable tips that fit into a socket on the end of the shaft and are held in mechanically or magnetically. These often have a hollow handle that contains various types and sizes of tips, and a reversible ratchet action that allows multiple full turns without repositioning the tip or the user's hand. A screwdriver is classified by its tip, which is shaped to fit the driving surfaces—slots, grooves, recesses, etc.—on the corresponding screw head. Proper use requires that the screwdriver's tip engage the head of a screw of the same size and type designation as the screwdriver tip. Screwdriver tips are available in a wide variety of types and sizes (List of screw drives). The two most common are the simple 'blade'-type for slotted screws, and Phillips, generically called "cross-recess", "cross-head", or "cross-point".
